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      1 /*
      2  * Copyright (C) 1999 Lars Knoll (knoll (at) kde.org)
      3  *           (C) 1999 Antti Koivisto (koivisto (at) kde.org)
      4  *           (C) 2000 Dirk Mueller (mueller (at) kde.org)
      5  *           (C) 2004 Allan Sandfeld Jensen (kde (at) carewolf.com)
      6  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2011 Apple Inc. All rights reserved.
      7  * Copyright (C) 2009 Google Inc. All rights reserved.
      8  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
      9  *
     10  * This library is free software; you can redistribute it and/or
     11  * modify it under the terms of the GNU Library General Public
     12  * License as published by the Free Software Foundation; either
     13  * version 2 of the License, or (at your option) any later version.
     14  *
     15  * This library is distributed in the hope that it will be useful,
     16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
     17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     18  * Library General Public License for more details.
     19  *
     20  * You should have received a copy of the GNU Library General Public License
     21  * along with this library; see the file COPYING.LIB.  If not, write to
     22  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
     23  * Boston, MA 02110-1301, USA.
     24  *
     25  */
     26 
     27 #include "config.h"
     28 #include "core/rendering/RenderObject.h"
     29 
     30 #include "core/HTMLNames.h"
     31 #include "core/accessibility/AXObjectCache.h"
     32 #include "core/css/resolver/StyleResolver.h"
     33 #include "core/dom/ElementTraversal.h"
     34 #include "core/dom/StyleEngine.h"
     35 #include "core/dom/shadow/ShadowRoot.h"
     36 #include "core/editing/EditingBoundary.h"
     37 #include "core/editing/FrameSelection.h"
     38 #include "core/editing/htmlediting.h"
     39 #include "core/fetch/ResourceLoadPriorityOptimizer.h"
     40 #include "core/fetch/ResourceLoader.h"
     41 #include "core/frame/EventHandlerRegistry.h"
     42 #include "core/frame/FrameView.h"
     43 #include "core/frame/LocalFrame.h"
     44 #include "core/frame/Settings.h"
     45 #include "core/frame/UseCounter.h"
     46 #include "core/html/HTMLAnchorElement.h"
     47 #include "core/html/HTMLElement.h"
     48 #include "core/html/HTMLHtmlElement.h"
     49 #include "core/html/HTMLTableCellElement.h"
     50 #include "core/html/HTMLTableElement.h"
     51 #include "core/page/AutoscrollController.h"
     52 #include "core/page/EventHandler.h"
     53 #include "core/page/Page.h"
     54 #include "core/paint/ObjectPainter.h"
     55 #include "core/rendering/FlowThreadController.h"
     56 #include "core/rendering/HitTestResult.h"
     57 #include "core/rendering/RenderCounter.h"
     58 #include "core/rendering/RenderDeprecatedFlexibleBox.h"
     59 #include "core/rendering/RenderFlexibleBox.h"
     60 #include "core/rendering/RenderFlowThread.h"
     61 #include "core/rendering/RenderGeometryMap.h"
     62 #include "core/rendering/RenderGrid.h"
     63 #include "core/rendering/RenderImage.h"
     64 #include "core/rendering/RenderImageResourceStyleImage.h"
     65 #include "core/rendering/RenderInline.h"
     66 #include "core/rendering/RenderLayer.h"
     67 #include "core/rendering/RenderListItem.h"
     68 #include "core/rendering/RenderMarquee.h"
     69 #include "core/rendering/RenderObjectInlines.h"
     70 #include "core/rendering/RenderPart.h"
     71 #include "core/rendering/RenderScrollbarPart.h"
     72 #include "core/rendering/RenderTableCaption.h"
     73 #include "core/rendering/RenderTableCell.h"
     74 #include "core/rendering/RenderTableCol.h"
     75 #include "core/rendering/RenderTableRow.h"
     76 #include "core/rendering/RenderTheme.h"
     77 #include "core/rendering/RenderView.h"
     78 #include "core/rendering/compositing/CompositedLayerMapping.h"
     79 #include "core/rendering/compositing/RenderLayerCompositor.h"
     80 #include "core/rendering/style/ContentData.h"
     81 #include "core/rendering/style/ShadowList.h"
     82 #include "platform/JSONValues.h"
     83 #include "platform/Partitions.h"
     84 #include "platform/RuntimeEnabledFeatures.h"
     85 #include "platform/TraceEvent.h"
     86 #include "platform/TracedValue.h"
     87 #include "platform/geometry/TransformState.h"
     88 #include "platform/graphics/FirstPaintInvalidationTracking.h"
     89 #include "platform/graphics/GraphicsContext.h"
     90 #include "wtf/RefCountedLeakCounter.h"
     91 #include "wtf/text/StringBuilder.h"
     92 #include "wtf/text/WTFString.h"
     93 #include <algorithm>
     94 #ifndef NDEBUG
     95 #include <stdio.h>
     96 #endif
     97 
     98 namespace blink {
     99 
    100 namespace {
    101 
    102 static bool gModifyRenderTreeStructureAnyState = false;
    103 
    104 typedef WillBeHeapHashSet<RawPtrWillBeWeakMember<const RenderObject> > RenderObjectWeakSet;
    105 RenderObjectWeakSet& renderObjectNeverHadPaintInvalidationSet()
    106 {
    107     DEFINE_STATIC_LOCAL(OwnPtrWillBePersistent<RenderObjectWeakSet>, set, (adoptPtrWillBeNoop(new RenderObjectWeakSet())));
    108     return *set;
    109 }
    110 
    111 } // namespace
    112 
    113 using namespace HTMLNames;
    114 
    115 #if ENABLE(ASSERT)
    116 
    117 RenderObject::SetLayoutNeededForbiddenScope::SetLayoutNeededForbiddenScope(RenderObject& renderObject)
    118     : m_renderObject(renderObject)
    119     , m_preexistingForbidden(m_renderObject.isSetNeedsLayoutForbidden())
    120 {
    121     m_renderObject.setNeedsLayoutIsForbidden(true);
    122 }
    123 
    124 RenderObject::SetLayoutNeededForbiddenScope::~SetLayoutNeededForbiddenScope()
    125 {
    126     m_renderObject.setNeedsLayoutIsForbidden(m_preexistingForbidden);
    127 }
    128 #endif
    129 
    130 struct SameSizeAsRenderObject {
    131     virtual ~SameSizeAsRenderObject() { } // Allocate vtable pointer.
    132     void* pointers[5];
    133 #if ENABLE(ASSERT)
    134     unsigned m_debugBitfields : 2;
    135 #if ENABLE(OILPAN)
    136     unsigned m_oilpanBitfields : 1;
    137 #endif
    138 #endif
    139     unsigned m_bitfields;
    140     unsigned m_bitfields2;
    141     LayoutRect rect; // Stores the previous paint invalidation rect.
    142     LayoutPoint position; // Stores the previous position from the paint invalidation container.
    143 };
    144 
    145 COMPILE_ASSERT(sizeof(RenderObject) == sizeof(SameSizeAsRenderObject), RenderObject_should_stay_small);
    146 
    147 bool RenderObject::s_affectsParentBlock = false;
    148 
    149 #if !ENABLE(OILPAN)
    150 void* RenderObject::operator new(size_t sz)
    151 {
    152     ASSERT(isMainThread());
    153     return partitionAlloc(Partitions::getRenderingPartition(), sz);
    154 }
    155 
    156 void RenderObject::operator delete(void* ptr)
    157 {
    158     ASSERT(isMainThread());
    159     partitionFree(ptr);
    160 }
    161 #endif
    162 
    163 RenderObject* RenderObject::createObject(Element* element, RenderStyle* style)
    164 {
    165     ASSERT(isAllowedToModifyRenderTreeStructure(element->document()));
    166 
    167     // Minimal support for content properties replacing an entire element.
    168     // Works only if we have exactly one piece of content and it's a URL.
    169     // Otherwise acts as if we didn't support this feature.
    170     const ContentData* contentData = style->contentData();
    171     if (contentData && !contentData->next() && contentData->isImage() && !element->isPseudoElement()) {
    172         RenderImage* image = new RenderImage(element);
    173         // RenderImageResourceStyleImage requires a style being present on the image but we don't want to
    174         // trigger a style change now as the node is not fully attached. Moving this code to style change
    175         // doesn't make sense as it should be run once at renderer creation.
    176         image->setStyleInternal(style);
    177         if (const StyleImage* styleImage = toImageContentData(contentData)->image()) {
    178             image->setImageResource(RenderImageResourceStyleImage::create(const_cast<StyleImage*>(styleImage)));
    179             image->setIsGeneratedContent();
    180         } else
    181             image->setImageResource(RenderImageResource::create());
    182         image->setStyleInternal(nullptr);
    183         return image;
    184     }
    185 
    186     switch (style->display()) {
    187     case NONE:
    188         return 0;
    189     case INLINE:
    190         return new RenderInline(element);
    191     case BLOCK:
    192     case INLINE_BLOCK:
    193         return new RenderBlockFlow(element);
    194     case LIST_ITEM:
    195         return new RenderListItem(element);
    196     case TABLE:
    197     case INLINE_TABLE:
    198         return new RenderTable(element);
    199     case TABLE_ROW_GROUP:
    200     case TABLE_HEADER_GROUP:
    201     case TABLE_FOOTER_GROUP:
    202         return new RenderTableSection(element);
    203     case TABLE_ROW:
    204         return new RenderTableRow(element);
    205     case TABLE_COLUMN_GROUP:
    206     case TABLE_COLUMN:
    207         return new RenderTableCol(element);
    208     case TABLE_CELL:
    209         return new RenderTableCell(element);
    210     case TABLE_CAPTION:
    211         return new RenderTableCaption(element);
    212     case BOX:
    213     case INLINE_BOX:
    214         return new RenderDeprecatedFlexibleBox(*element);
    215     case FLEX:
    216     case INLINE_FLEX:
    217         return new RenderFlexibleBox(element);
    218     case GRID:
    219     case INLINE_GRID:
    220         return new RenderGrid(element);
    221     }
    222 
    223     return 0;
    224 }
    225 
    226 DEFINE_DEBUG_ONLY_GLOBAL(WTF::RefCountedLeakCounter, renderObjectCounter, ("RenderObject"));
    227 unsigned RenderObject::s_instanceCount = 0;
    228 
    229 RenderObject::RenderObject(Node* node)
    230     : ImageResourceClient()
    231     , m_style(nullptr)
    232     , m_node(node)
    233     , m_parent(nullptr)
    234     , m_previous(nullptr)
    235     , m_next(nullptr)
    236 #if ENABLE(ASSERT)
    237     , m_hasAXObject(false)
    238     , m_setNeedsLayoutForbidden(false)
    239 #if ENABLE(OILPAN)
    240     , m_didCallDestroy(false)
    241 #endif
    242 #endif
    243     , m_bitfields(node)
    244 {
    245     if (firstPaintInvalidationTrackingEnabled())
    246         renderObjectNeverHadPaintInvalidationSet().add(this);
    247 
    248 #ifndef NDEBUG
    249     renderObjectCounter.increment();
    250 #endif
    251     ++s_instanceCount;
    252 }
    253 
    254 RenderObject::~RenderObject()
    255 {
    256     if (firstPaintInvalidationTrackingEnabled())
    257         renderObjectNeverHadPaintInvalidationSet().remove(this);
    258 
    259     ASSERT(!m_hasAXObject);
    260 #if ENABLE(OILPAN)
    261     ASSERT(m_didCallDestroy);
    262 #endif
    263 #ifndef NDEBUG
    264     renderObjectCounter.decrement();
    265 #endif
    266     --s_instanceCount;
    267 }
    268 
    269 void RenderObject::trace(Visitor* visitor)
    270 {
    271     visitor->trace(m_node);
    272     visitor->trace(m_parent);
    273     visitor->trace(m_previous);
    274     visitor->trace(m_next);
    275 }
    276 
    277 String RenderObject::debugName() const
    278 {
    279     StringBuilder name;
    280     name.append(renderName());
    281 
    282     if (Node* node = this->node()) {
    283         name.append(' ');
    284         name.append(node->debugName());
    285     }
    286 
    287     return name.toString();
    288 }
    289 
    290 bool RenderObject::isDescendantOf(const RenderObject* obj) const
    291 {
    292     for (const RenderObject* r = this; r; r = r->m_parent) {
    293         if (r == obj)
    294             return true;
    295     }
    296     return false;
    297 }
    298 
    299 bool RenderObject::isHR() const
    300 {
    301     return isHTMLHRElement(node());
    302 }
    303 
    304 bool RenderObject::isLegend() const
    305 {
    306     return isHTMLLegendElement(node());
    307 }
    308 
    309 void RenderObject::setFlowThreadStateIncludingDescendants(FlowThreadState state)
    310 {
    311     for (RenderObject *object = this; object; object = object->nextInPreOrder(this)) {
    312         // If object is a fragmentation context it already updated the descendants flag accordingly.
    313         if (object->isRenderFlowThread())
    314             continue;
    315         ASSERT(state != object->flowThreadState());
    316         object->setFlowThreadState(state);
    317     }
    318 }
    319 
    320 bool RenderObject::requiresAnonymousTableWrappers(const RenderObject* newChild) const
    321 {
    322     // Check should agree with:
    323     // CSS 2.1 Tables: 17.2.1 Anonymous table objects
    324     // http://www.w3.org/TR/CSS21/tables.html#anonymous-boxes
    325     if (newChild->isRenderTableCol()) {
    326         const RenderTableCol* newTableColumn = toRenderTableCol(newChild);
    327         bool isColumnInColumnGroup = newTableColumn->isTableColumn() && isRenderTableCol();
    328         return !isTable() && !isColumnInColumnGroup;
    329     } else if (newChild->isTableCaption())
    330         return !isTable();
    331     else if (newChild->isTableSection())
    332         return !isTable();
    333     else if (newChild->isTableRow())
    334         return !isTableSection();
    335     else if (newChild->isTableCell())
    336         return !isTableRow();
    337     return false;
    338 }
    339 
    340 void RenderObject::addChild(RenderObject* newChild, RenderObject* beforeChild)
    341 {
    342     ASSERT(isAllowedToModifyRenderTreeStructure(document()));
    343 
    344     RenderObjectChildList* children = virtualChildren();
    345     ASSERT(children);
    346     if (!children)
    347         return;
    348 
    349     if (requiresAnonymousTableWrappers(newChild)) {
    350         // Generate an anonymous table or reuse existing one from previous child
    351         // Per: 17.2.1 Anonymous table objects 3. Generate missing parents
    352         // http://www.w3.org/TR/CSS21/tables.html#anonymous-boxes
    353         RenderTable* table;
    354         RenderObject* afterChild = beforeChild ? beforeChild->previousSibling() : children->lastChild();
    355         if (afterChild && afterChild->isAnonymous() && afterChild->isTable() && !afterChild->isBeforeContent())
    356             table = toRenderTable(afterChild);
    357         else {
    358             table = RenderTable::createAnonymousWithParentRenderer(this);
    359             addChild(table, beforeChild);
    360         }
    361         table->addChild(newChild);
    362     } else
    363         children->insertChildNode(this, newChild, beforeChild);
    364 
    365     if (newChild->isText() && newChild->style()->textTransform() == CAPITALIZE)
    366         toRenderText(newChild)->transformText();
    367 
    368     // SVG creates renderers for <g display="none">, as SVG requires children of hidden
    369     // <g>s to have renderers - at least that's how our implementation works. Consider:
    370     // <g display="none"><foreignObject><body style="position: relative">FOO...
    371     // - layerTypeRequired() would return true for the <body>, creating a new RenderLayer
    372     // - when the document is painted, both layers are painted. The <body> layer doesn't
    373     //   know that it's inside a "hidden SVG subtree", and thus paints, even if it shouldn't.
    374     // To avoid the problem alltogether, detect early if we're inside a hidden SVG subtree
    375     // and stop creating layers at all for these cases - they're not used anyways.
    376     if (newChild->hasLayer() && !layerCreationAllowedForSubtree())
    377         toRenderLayerModelObject(newChild)->layer()->removeOnlyThisLayer();
    378 }
    379 
    380 void RenderObject::removeChild(RenderObject* oldChild)
    381 {
    382     ASSERT(isAllowedToModifyRenderTreeStructure(document()));
    383 
    384     RenderObjectChildList* children = virtualChildren();
    385     ASSERT(children);
    386     if (!children)
    387         return;
    388 
    389     children->removeChildNode(this, oldChild);
    390 }
    391 
    392 RenderObject* RenderObject::nextInPreOrder() const
    393 {
    394     if (RenderObject* o = slowFirstChild())
    395         return o;
    396 
    397     return nextInPreOrderAfterChildren();
    398 }
    399 
    400 RenderObject* RenderObject::nextInPreOrderAfterChildren() const
    401 {
    402     RenderObject* o = nextSibling();
    403     if (!o) {
    404         o = parent();
    405         while (o && !o->nextSibling())
    406             o = o->parent();
    407         if (o)
    408             o = o->nextSibling();
    409     }
    410 
    411     return o;
    412 }
    413 
    414 RenderObject* RenderObject::nextInPreOrder(const RenderObject* stayWithin) const
    415 {
    416     if (RenderObject* o = slowFirstChild())
    417         return o;
    418 
    419     return nextInPreOrderAfterChildren(stayWithin);
    420 }
    421 
    422 RenderObject* RenderObject::nextInPreOrderAfterChildren(const RenderObject* stayWithin) const
    423 {
    424     if (this == stayWithin)
    425         return 0;
    426 
    427     const RenderObject* current = this;
    428     RenderObject* next = current->nextSibling();
    429     for (; !next; next = current->nextSibling()) {
    430         current = current->parent();
    431         if (!current || current == stayWithin)
    432             return 0;
    433     }
    434     return next;
    435 }
    436 
    437 RenderObject* RenderObject::previousInPreOrder() const
    438 {
    439     if (RenderObject* o = previousSibling()) {
    440         while (RenderObject* lastChild = o->slowLastChild())
    441             o = lastChild;
    442         return o;
    443     }
    444 
    445     return parent();
    446 }
    447 
    448 RenderObject* RenderObject::previousInPreOrder(const RenderObject* stayWithin) const
    449 {
    450     if (this == stayWithin)
    451         return 0;
    452 
    453     return previousInPreOrder();
    454 }
    455 
    456 RenderObject* RenderObject::childAt(unsigned index) const
    457 {
    458     RenderObject* child = slowFirstChild();
    459     for (unsigned i = 0; child && i < index; i++)
    460         child = child->nextSibling();
    461     return child;
    462 }
    463 
    464 RenderObject* RenderObject::lastLeafChild() const
    465 {
    466     RenderObject* r = slowLastChild();
    467     while (r) {
    468         RenderObject* n = 0;
    469         n = r->slowLastChild();
    470         if (!n)
    471             break;
    472         r = n;
    473     }
    474     return r;
    475 }
    476 
    477 static void addLayers(RenderObject* obj, RenderLayer* parentLayer, RenderObject*& newObject,
    478                       RenderLayer*& beforeChild)
    479 {
    480     if (obj->hasLayer()) {
    481         if (!beforeChild && newObject) {
    482             // We need to figure out the layer that follows newObject. We only do
    483             // this the first time we find a child layer, and then we update the
    484             // pointer values for newObject and beforeChild used by everyone else.
    485             beforeChild = newObject->parent()->findNextLayer(parentLayer, newObject);
    486             newObject = 0;
    487         }
    488         parentLayer->addChild(toRenderLayerModelObject(obj)->layer(), beforeChild);
    489         return;
    490     }
    491 
    492     for (RenderObject* curr = obj->slowFirstChild(); curr; curr = curr->nextSibling())
    493         addLayers(curr, parentLayer, newObject, beforeChild);
    494 }
    495 
    496 void RenderObject::addLayers(RenderLayer* parentLayer)
    497 {
    498     if (!parentLayer)
    499         return;
    500 
    501     RenderObject* object = this;
    502     RenderLayer* beforeChild = 0;
    503     blink::addLayers(this, parentLayer, object, beforeChild);
    504 }
    505 
    506 void RenderObject::removeLayers(RenderLayer* parentLayer)
    507 {
    508     if (!parentLayer)
    509         return;
    510 
    511     if (hasLayer()) {
    512         parentLayer->removeChild(toRenderLayerModelObject(this)->layer());
    513         return;
    514     }
    515 
    516     for (RenderObject* curr = slowFirstChild(); curr; curr = curr->nextSibling())
    517         curr->removeLayers(parentLayer);
    518 }
    519 
    520 void RenderObject::moveLayers(RenderLayer* oldParent, RenderLayer* newParent)
    521 {
    522     if (!newParent)
    523         return;
    524 
    525     if (hasLayer()) {
    526         RenderLayer* layer = toRenderLayerModelObject(this)->layer();
    527         ASSERT(oldParent == layer->parent());
    528         if (oldParent)
    529             oldParent->removeChild(layer);
    530         newParent->addChild(layer);
    531         return;
    532     }
    533 
    534     for (RenderObject* curr = slowFirstChild(); curr; curr = curr->nextSibling())
    535         curr->moveLayers(oldParent, newParent);
    536 }
    537 
    538 RenderLayer* RenderObject::findNextLayer(RenderLayer* parentLayer, RenderObject* startPoint,
    539                                          bool checkParent)
    540 {
    541     // Error check the parent layer passed in. If it's null, we can't find anything.
    542     if (!parentLayer)
    543         return 0;
    544 
    545     // Step 1: If our layer is a child of the desired parent, then return our layer.
    546     RenderLayer* ourLayer = hasLayer() ? toRenderLayerModelObject(this)->layer() : 0;
    547     if (ourLayer && ourLayer->parent() == parentLayer)
    548         return ourLayer;
    549 
    550     // Step 2: If we don't have a layer, or our layer is the desired parent, then descend
    551     // into our siblings trying to find the next layer whose parent is the desired parent.
    552     if (!ourLayer || ourLayer == parentLayer) {
    553         for (RenderObject* curr = startPoint ? startPoint->nextSibling() : slowFirstChild();
    554              curr; curr = curr->nextSibling()) {
    555             RenderLayer* nextLayer = curr->findNextLayer(parentLayer, 0, false);
    556             if (nextLayer)
    557                 return nextLayer;
    558         }
    559     }
    560 
    561     // Step 3: If our layer is the desired parent layer, then we're finished. We didn't
    562     // find anything.
    563     if (parentLayer == ourLayer)
    564         return 0;
    565 
    566     // Step 4: If |checkParent| is set, climb up to our parent and check its siblings that
    567     // follow us to see if we can locate a layer.
    568     if (checkParent && parent())
    569         return parent()->findNextLayer(parentLayer, this, true);
    570 
    571     return 0;
    572 }
    573 
    574 RenderLayer* RenderObject::enclosingLayer() const
    575 {
    576     for (const RenderObject* current = this; current; current = current->parent()) {
    577         if (current->hasLayer())
    578             return toRenderLayerModelObject(current)->layer();
    579     }
    580     // FIXME: we should get rid of detached render subtrees, at which point this code should
    581     // not be reached. crbug.com/411429
    582     return 0;
    583 }
    584 
    585 bool RenderObject::scrollRectToVisible(const LayoutRect& rect, const ScrollAlignment& alignX, const ScrollAlignment& alignY)
    586 {
    587     RenderBox* enclosingBox = this->enclosingBox();
    588     if (!enclosingBox)
    589         return false;
    590 
    591     enclosingBox->scrollRectToVisible(rect, alignX, alignY);
    592     return true;
    593 }
    594 
    595 RenderBox* RenderObject::enclosingBox() const
    596 {
    597     RenderObject* curr = const_cast<RenderObject*>(this);
    598     while (curr) {
    599         if (curr->isBox())
    600             return toRenderBox(curr);
    601         curr = curr->parent();
    602     }
    603 
    604     ASSERT_NOT_REACHED();
    605     return 0;
    606 }
    607 
    608 RenderBoxModelObject* RenderObject::enclosingBoxModelObject() const
    609 {
    610     RenderObject* curr = const_cast<RenderObject*>(this);
    611     while (curr) {
    612         if (curr->isBoxModelObject())
    613             return toRenderBoxModelObject(curr);
    614         curr = curr->parent();
    615     }
    616 
    617     ASSERT_NOT_REACHED();
    618     return 0;
    619 }
    620 
    621 RenderBox* RenderObject::enclosingScrollableBox() const
    622 {
    623     for (RenderObject* ancestor = parent(); ancestor; ancestor = ancestor->parent()) {
    624         if (!ancestor->isBox())
    625             continue;
    626 
    627         RenderBox* ancestorBox = toRenderBox(ancestor);
    628         if (ancestorBox->canBeScrolledAndHasScrollableArea())
    629             return ancestorBox;
    630     }
    631 
    632     return 0;
    633 }
    634 
    635 RenderFlowThread* RenderObject::locateFlowThreadContainingBlock() const
    636 {
    637     ASSERT(flowThreadState() != NotInsideFlowThread);
    638 
    639     // See if we have the thread cached because we're in the middle of layout.
    640     RenderFlowThread* flowThread = view()->flowThreadController()->currentRenderFlowThread();
    641     if (flowThread)
    642         return flowThread;
    643 
    644     // Not in the middle of layout so have to find the thread the slow way.
    645     RenderObject* curr = const_cast<RenderObject*>(this);
    646     while (curr) {
    647         if (curr->isRenderFlowThread())
    648             return toRenderFlowThread(curr);
    649         curr = curr->containingBlock();
    650     }
    651     return 0;
    652 }
    653 
    654 bool RenderObject::skipInvalidationWhenLaidOutChildren() const
    655 {
    656     if (!neededLayoutBecauseOfChildren())
    657         return false;
    658 
    659     // SVG renderers need to be invalidated when their children are laid out.
    660     // RenderBlocks with line boxes are responsible to invalidate them so we can't ignore them.
    661     if (isSVG() || (isRenderBlockFlow() && toRenderBlockFlow(this)->firstLineBox()))
    662         return false;
    663 
    664     return rendererHasNoBoxEffect();
    665 }
    666 
    667 RenderBlock* RenderObject::firstLineBlock() const
    668 {
    669     return 0;
    670 }
    671 
    672 static inline bool objectIsRelayoutBoundary(const RenderObject* object)
    673 {
    674     // FIXME: In future it may be possible to broaden these conditions in order to improve performance.
    675     if (object->isTextControl())
    676         return true;
    677 
    678     if (object->isSVGRoot())
    679         return true;
    680 
    681     if (!object->hasOverflowClip())
    682         return false;
    683 
    684     if (object->style()->width().isIntrinsicOrAuto() || object->style()->height().isIntrinsicOrAuto() || object->style()->height().isPercent())
    685         return false;
    686 
    687     // Table parts can't be relayout roots since the table is responsible for layouting all the parts.
    688     if (object->isTablePart())
    689         return false;
    690 
    691     return true;
    692 }
    693 
    694 void RenderObject::markContainingBlocksForLayout(bool scheduleRelayout, RenderObject* newRoot, SubtreeLayoutScope* layouter)
    695 {
    696     ASSERT(!scheduleRelayout || !newRoot);
    697     ASSERT(!isSetNeedsLayoutForbidden());
    698     ASSERT(!layouter || this != layouter->root());
    699 
    700     RenderObject* object = container();
    701     RenderObject* last = this;
    702 
    703     bool simplifiedNormalFlowLayout = needsSimplifiedNormalFlowLayout() && !selfNeedsLayout() && !normalChildNeedsLayout();
    704 
    705     while (object) {
    706         if (object->selfNeedsLayout())
    707             return;
    708 
    709         // Don't mark the outermost object of an unrooted subtree. That object will be
    710         // marked when the subtree is added to the document.
    711         RenderObject* container = object->container();
    712         if (!container && !object->isRenderView())
    713             return;
    714         if (!last->isText() && last->style()->hasOutOfFlowPosition()) {
    715             bool willSkipRelativelyPositionedInlines = !object->isRenderBlock() || object->isAnonymousBlock();
    716             // Skip relatively positioned inlines and anonymous blocks to get to the enclosing RenderBlock.
    717             while (object && (!object->isRenderBlock() || object->isAnonymousBlock()))
    718                 object = object->container();
    719             if (!object || object->posChildNeedsLayout())
    720                 return;
    721             if (willSkipRelativelyPositionedInlines)
    722                 container = object->container();
    723             object->setPosChildNeedsLayout(true);
    724             simplifiedNormalFlowLayout = true;
    725             ASSERT(!object->isSetNeedsLayoutForbidden());
    726         } else if (simplifiedNormalFlowLayout) {
    727             if (object->needsSimplifiedNormalFlowLayout())
    728                 return;
    729             object->setNeedsSimplifiedNormalFlowLayout(true);
    730             ASSERT(!object->isSetNeedsLayoutForbidden());
    731         } else {
    732             if (object->normalChildNeedsLayout())
    733                 return;
    734             object->setNormalChildNeedsLayout(true);
    735             ASSERT(!object->isSetNeedsLayoutForbidden());
    736         }
    737 
    738         if (layouter) {
    739             layouter->addRendererToLayout(object);
    740             if (object == layouter->root())
    741                 return;
    742         }
    743 
    744         if (object == newRoot)
    745             return;
    746 
    747         last = object;
    748         if (scheduleRelayout && objectIsRelayoutBoundary(last))
    749             break;
    750         object = container;
    751     }
    752 
    753     if (scheduleRelayout)
    754         last->scheduleRelayout();
    755 }
    756 
    757 #if ENABLE(ASSERT)
    758 void RenderObject::checkBlockPositionedObjectsNeedLayout()
    759 {
    760     ASSERT(!needsLayout());
    761 
    762     if (isRenderBlock())
    763         toRenderBlock(this)->checkPositionedObjectsNeedLayout();
    764 }
    765 #endif
    766 
    767 void RenderObject::setPreferredLogicalWidthsDirty(MarkingBehavior markParents)
    768 {
    769     m_bitfields.setPreferredLogicalWidthsDirty(true);
    770     if (markParents == MarkContainingBlockChain && (isText() || !style()->hasOutOfFlowPosition()))
    771         invalidateContainerPreferredLogicalWidths();
    772 }
    773 
    774 void RenderObject::clearPreferredLogicalWidthsDirty()
    775 {
    776     m_bitfields.setPreferredLogicalWidthsDirty(false);
    777 }
    778 
    779 void RenderObject::invalidateContainerPreferredLogicalWidths()
    780 {
    781     // In order to avoid pathological behavior when inlines are deeply nested, we do include them
    782     // in the chain that we mark dirty (even though they're kind of irrelevant).
    783     RenderObject* o = isTableCell() ? containingBlock() : container();
    784     while (o && !o->preferredLogicalWidthsDirty()) {
    785         // Don't invalidate the outermost object of an unrooted subtree. That object will be
    786         // invalidated when the subtree is added to the document.
    787         RenderObject* container = o->isTableCell() ? o->containingBlock() : o->container();
    788         if (!container && !o->isRenderView())
    789             break;
    790 
    791         o->m_bitfields.setPreferredLogicalWidthsDirty(true);
    792         if (o->style()->hasOutOfFlowPosition())
    793             // A positioned object has no effect on the min/max width of its containing block ever.
    794             // We can optimize this case and not go up any further.
    795             break;
    796         o = container;
    797     }
    798 }
    799 
    800 RenderBlock* RenderObject::containerForFixedPosition(const RenderLayerModelObject* paintInvalidationContainer, bool* paintInvalidationContainerSkipped) const
    801 {
    802     ASSERT(!paintInvalidationContainerSkipped || !*paintInvalidationContainerSkipped);
    803     ASSERT(!isText());
    804     ASSERT(style()->position() == FixedPosition);
    805 
    806     RenderObject* ancestor = parent();
    807     for (; ancestor && !ancestor->canContainFixedPositionObjects(); ancestor = ancestor->parent()) {
    808         if (paintInvalidationContainerSkipped && ancestor == paintInvalidationContainer)
    809             *paintInvalidationContainerSkipped = true;
    810     }
    811 
    812     ASSERT(!ancestor || !ancestor->isAnonymousBlock());
    813     return toRenderBlock(ancestor);
    814 }
    815 
    816 RenderBlock* RenderObject::containingBlock() const
    817 {
    818     RenderObject* o = parent();
    819     if (!o && isRenderScrollbarPart())
    820         o = toRenderScrollbarPart(this)->rendererOwningScrollbar();
    821     if (!isText() && m_style->position() == FixedPosition) {
    822         return containerForFixedPosition();
    823     } else if (!isText() && m_style->position() == AbsolutePosition) {
    824         while (o) {
    825             // For relpositioned inlines, we return the nearest non-anonymous enclosing block. We don't try
    826             // to return the inline itself.  This allows us to avoid having a positioned objects
    827             // list in all RenderInlines and lets us return a strongly-typed RenderBlock* result
    828             // from this method.  The container() method can actually be used to obtain the
    829             // inline directly.
    830             if (o->style()->position() != StaticPosition && (!o->isInline() || o->isReplaced()))
    831                 break;
    832 
    833             if (o->canContainFixedPositionObjects())
    834                 break;
    835 
    836             if (o->style()->hasInFlowPosition() && o->isInline() && !o->isReplaced()) {
    837                 o = o->containingBlock();
    838                 break;
    839             }
    840 
    841             o = o->parent();
    842         }
    843 
    844         if (o && !o->isRenderBlock())
    845             o = o->containingBlock();
    846 
    847         while (o && o->isAnonymousBlock())
    848             o = o->containingBlock();
    849     } else {
    850         while (o && ((o->isInline() && !o->isReplaced()) || !o->isRenderBlock()))
    851             o = o->parent();
    852     }
    853 
    854     if (!o || !o->isRenderBlock())
    855         return 0; // This can still happen in case of an orphaned tree
    856 
    857     return toRenderBlock(o);
    858 }
    859 
    860 bool RenderObject::canRenderBorderImage() const
    861 {
    862     if (!style()->hasBorder())
    863         return false;
    864 
    865     StyleImage* borderImage = style()->borderImage().image();
    866     return borderImage && borderImage->canRender(*this, style()->effectiveZoom()) && borderImage->isLoaded();
    867 }
    868 
    869 bool RenderObject::mustInvalidateFillLayersPaintOnWidthChange(const FillLayer& layer) const
    870 {
    871     // Nobody will use multiple layers without wanting fancy positioning.
    872     if (layer.next())
    873         return true;
    874 
    875     // Make sure we have a valid image.
    876     StyleImage* img = layer.image();
    877     if (!img || !img->canRender(*this, style()->effectiveZoom()))
    878         return false;
    879 
    880     if (layer.repeatX() != RepeatFill && layer.repeatX() != NoRepeatFill)
    881         return true;
    882 
    883     if (layer.xPosition().isPercent() && !layer.xPosition().isZero())
    884         return true;
    885 
    886     if (layer.backgroundXOrigin() != LeftEdge)
    887         return true;
    888 
    889     EFillSizeType sizeType = layer.sizeType();
    890 
    891     if (sizeType == Contain || sizeType == Cover)
    892         return true;
    893 
    894     if (sizeType == SizeLength) {
    895         if (layer.sizeLength().width().isPercent() && !layer.sizeLength().width().isZero())
    896             return true;
    897         if (img->isGeneratedImage() && layer.sizeLength().width().isAuto())
    898             return true;
    899     } else if (img->usesImageContainerSize()) {
    900         return true;
    901     }
    902 
    903     return false;
    904 }
    905 
    906 bool RenderObject::mustInvalidateFillLayersPaintOnHeightChange(const FillLayer& layer) const
    907 {
    908     // Nobody will use multiple layers without wanting fancy positioning.
    909     if (layer.next())
    910         return true;
    911 
    912     // Make sure we have a valid image.
    913     StyleImage* img = layer.image();
    914     if (!img || !img->canRender(*this, style()->effectiveZoom()))
    915         return false;
    916 
    917     if (layer.repeatY() != RepeatFill && layer.repeatY() != NoRepeatFill)
    918         return true;
    919 
    920     if (layer.yPosition().isPercent() && !layer.yPosition().isZero())
    921         return true;
    922 
    923     if (layer.backgroundYOrigin() != TopEdge)
    924         return true;
    925 
    926     EFillSizeType sizeType = layer.sizeType();
    927 
    928     if (sizeType == Contain || sizeType == Cover)
    929         return true;
    930 
    931     if (sizeType == SizeLength) {
    932         if (layer.sizeLength().height().isPercent() && !layer.sizeLength().height().isZero())
    933             return true;
    934         if (img->isGeneratedImage() && layer.sizeLength().height().isAuto())
    935             return true;
    936     } else if (img->usesImageContainerSize()) {
    937         return true;
    938     }
    939 
    940     return false;
    941 }
    942 
    943 bool RenderObject::mustInvalidateBackgroundOrBorderPaintOnWidthChange() const
    944 {
    945     if (hasMask() && mustInvalidateFillLayersPaintOnWidthChange(style()->maskLayers()))
    946         return true;
    947 
    948     // If we don't have a background/border/mask, then nothing to do.
    949     if (!hasBoxDecorationBackground())
    950         return false;
    951 
    952     if (mustInvalidateFillLayersPaintOnWidthChange(style()->backgroundLayers()))
    953         return true;
    954 
    955     // Our fill layers are ok. Let's check border.
    956     if (style()->hasBorder() && canRenderBorderImage())
    957         return true;
    958 
    959     return false;
    960 }
    961 
    962 bool RenderObject::mustInvalidateBackgroundOrBorderPaintOnHeightChange() const
    963 {
    964     if (hasMask() && mustInvalidateFillLayersPaintOnHeightChange(style()->maskLayers()))
    965         return true;
    966 
    967     // If we don't have a background/border/mask, then nothing to do.
    968     if (!hasBoxDecorationBackground())
    969         return false;
    970 
    971     if (mustInvalidateFillLayersPaintOnHeightChange(style()->backgroundLayers()))
    972         return true;
    973 
    974     // Our fill layers are ok.  Let's check border.
    975     if (style()->hasBorder() && canRenderBorderImage())
    976         return true;
    977 
    978     return false;
    979 }
    980 
    981 void RenderObject::paintOutline(PaintInfo& paintInfo, const LayoutRect& paintRect)
    982 {
    983     ObjectPainter(*this).paintOutline(paintInfo, paintRect);
    984 }
    985 
    986 void RenderObject::addChildFocusRingRects(Vector<LayoutRect>& rects, const LayoutPoint& additionalOffset, const RenderLayerModelObject* paintContainer) const
    987 {
    988     for (RenderObject* current = slowFirstChild(); current; current = current->nextSibling()) {
    989         if (current->isText() || current->isListMarker())
    990             continue;
    991 
    992         if (current->isBox()) {
    993             RenderBox* box = toRenderBox(current);
    994             if (box->hasLayer()) {
    995                 Vector<LayoutRect> layerFocusRingRects;
    996                 box->addFocusRingRects(layerFocusRingRects, LayoutPoint(), box);
    997                 for (size_t i = 0; i < layerFocusRingRects.size(); ++i) {
    998                     FloatQuad quadInBox = box->localToContainerQuad(FloatQuad(layerFocusRingRects[i]), paintContainer);
    999                     LayoutRect rect = LayoutRect(quadInBox.boundingBox());
   1000                     if (!rect.isEmpty())
   1001                         rects.append(rect);
   1002                 }
   1003             } else {
   1004                 box->addFocusRingRects(rects, additionalOffset + box->locationOffset(), paintContainer);
   1005             }
   1006         } else {
   1007             current->addFocusRingRects(rects, additionalOffset, paintContainer);
   1008         }
   1009     }
   1010 }
   1011 
   1012 IntRect RenderObject::absoluteBoundingBoxRect() const
   1013 {
   1014     Vector<FloatQuad> quads;
   1015     absoluteQuads(quads);
   1016 
   1017     size_t n = quads.size();
   1018     if (!n)
   1019         return IntRect();
   1020 
   1021     IntRect result = quads[0].enclosingBoundingBox();
   1022     for (size_t i = 1; i < n; ++i)
   1023         result.unite(quads[i].enclosingBoundingBox());
   1024     return result;
   1025 }
   1026 
   1027 IntRect RenderObject::absoluteBoundingBoxRectIgnoringTransforms() const
   1028 {
   1029     FloatPoint absPos = localToAbsolute();
   1030     Vector<IntRect> rects;
   1031     absoluteRects(rects, flooredLayoutPoint(absPos));
   1032 
   1033     size_t n = rects.size();
   1034     if (!n)
   1035         return IntRect();
   1036 
   1037     LayoutRect result = rects[0];
   1038     for (size_t i = 1; i < n; ++i)
   1039         result.unite(rects[i]);
   1040     return pixelSnappedIntRect(result);
   1041 }
   1042 
   1043 IntRect RenderObject::absoluteFocusRingBoundingBoxRect() const
   1044 {
   1045     Vector<LayoutRect> rects;
   1046     const RenderLayerModelObject* container = containerForPaintInvalidation();
   1047     addFocusRingRects(rects, LayoutPoint(localToContainerPoint(FloatPoint(), container)), container);
   1048     return container->localToAbsoluteQuad(FloatQuad(unionRect(rects))).enclosingBoundingBox();
   1049 }
   1050 
   1051 FloatRect RenderObject::absoluteBoundingBoxRectForRange(const Range* range)
   1052 {
   1053     if (!range || !range->startContainer())
   1054         return FloatRect();
   1055 
   1056     range->ownerDocument().updateLayout();
   1057 
   1058     Vector<FloatQuad> quads;
   1059     range->textQuads(quads);
   1060 
   1061     FloatRect result;
   1062     for (size_t i = 0; i < quads.size(); ++i)
   1063         result.unite(quads[i].boundingBox());
   1064 
   1065     return result;
   1066 }
   1067 
   1068 void RenderObject::addAbsoluteRectForLayer(LayoutRect& result)
   1069 {
   1070     if (hasLayer())
   1071         result.unite(absoluteBoundingBoxRect());
   1072     for (RenderObject* current = slowFirstChild(); current; current = current->nextSibling())
   1073         current->addAbsoluteRectForLayer(result);
   1074 }
   1075 
   1076 LayoutRect RenderObject::paintingRootRect(LayoutRect& topLevelRect)
   1077 {
   1078     LayoutRect result = absoluteBoundingBoxRect();
   1079     topLevelRect = result;
   1080     for (RenderObject* current = slowFirstChild(); current; current = current->nextSibling())
   1081         current->addAbsoluteRectForLayer(result);
   1082     return result;
   1083 }
   1084 
   1085 void RenderObject::paint(PaintInfo&, const LayoutPoint&)
   1086 {
   1087 }
   1088 
   1089 void RenderObject::setHadPaintInvalidation()
   1090 {
   1091     if (firstPaintInvalidationTrackingEnabled())
   1092         renderObjectNeverHadPaintInvalidationSet().remove(this);
   1093 }
   1094 
   1095 bool RenderObject::hadPaintInvalidation() const
   1096 {
   1097     if (!firstPaintInvalidationTrackingEnabled())
   1098         return true;
   1099 
   1100     return !renderObjectNeverHadPaintInvalidationSet().contains(this);
   1101 }
   1102 
   1103 const RenderLayerModelObject* RenderObject::containerForPaintInvalidation() const
   1104 {
   1105     RELEASE_ASSERT(isRooted());
   1106     return adjustCompositedContainerForSpecialAncestors(enclosingCompositedContainer());
   1107 }
   1108 
   1109 const RenderLayerModelObject* RenderObject::enclosingCompositedContainer() const
   1110 {
   1111     RenderLayerModelObject* container = 0;
   1112     // FIXME: CompositingState is not necessarily up to date for many callers of this function.
   1113     DisableCompositingQueryAsserts disabler;
   1114 
   1115     if (RenderLayer* compositingLayer = enclosingLayer()->enclosingLayerForPaintInvalidationCrossingFrameBoundaries())
   1116         container = compositingLayer->renderer();
   1117     return container;
   1118 }
   1119 
   1120 const RenderLayerModelObject* RenderObject::adjustCompositedContainerForSpecialAncestors(const RenderLayerModelObject* paintInvalidationContainer) const
   1121 {
   1122     // If we have a flow thread, then we need to do individual paint invalidations within the RenderRegions instead.
   1123     // Return the flow thread as a paint invalidation container in order to create a chokepoint that allows us to change
   1124     // paint invalidation to do individual region paint invalidations.
   1125     if (RenderFlowThread* parentRenderFlowThread = flowThreadContainingBlock()) {
   1126         // If we have already found a paint invalidation container then we will invalidate paints in that container only if it is part of the same
   1127         // flow thread. Otherwise we will need to catch the paint invalidation call and send it to the flow thread.
   1128         if (!paintInvalidationContainer || paintInvalidationContainer->flowThreadContainingBlock() != parentRenderFlowThread)
   1129             paintInvalidationContainer = parentRenderFlowThread;
   1130     }
   1131 
   1132     if (paintInvalidationContainer)
   1133         return paintInvalidationContainer;
   1134 
   1135     RenderView* renderView = view();
   1136     while (renderView->frame()->ownerRenderer())
   1137         renderView = renderView->frame()->ownerRenderer()->view();
   1138     return renderView;
   1139 }
   1140 
   1141 bool RenderObject::isPaintInvalidationContainer() const
   1142 {
   1143     return hasLayer() && toRenderLayerModelObject(this)->layer()->isPaintInvalidationContainer();
   1144 }
   1145 
   1146 template <typename T>
   1147 void addJsonObjectForRect(TracedValue* value, const char* name, const T& rect)
   1148 {
   1149     value->beginDictionary(name);
   1150     value->setDouble("x", rect.x());
   1151     value->setDouble("y", rect.y());
   1152     value->setDouble("width", rect.width());
   1153     value->setDouble("height", rect.height());
   1154     value->endDictionary();
   1155 }
   1156 
   1157 template <typename T>
   1158 void addJsonObjectForPoint(TracedValue* value, const char* name, const T& point)
   1159 {
   1160     value->beginDictionary(name);
   1161     value->setDouble("x", point.x());
   1162     value->setDouble("y", point.y());
   1163     value->endDictionary();
   1164 }
   1165 
   1166 static PassRefPtr<TraceEvent::ConvertableToTraceFormat> jsonObjectForPaintInvalidationInfo(const LayoutRect& rect, const String& invalidationReason)
   1167 {
   1168     RefPtr<TracedValue> value = TracedValue::create();
   1169     addJsonObjectForRect(value.get(), "rect", rect);
   1170     value->setString("invalidation_reason", invalidationReason);
   1171     return value;
   1172 }
   1173 
   1174 LayoutRect RenderObject::computePaintInvalidationRect(const RenderLayerModelObject* paintInvalidationContainer, const PaintInvalidationState* paintInvalidationState) const
   1175 {
   1176     return clippedOverflowRectForPaintInvalidation(paintInvalidationContainer, paintInvalidationState);
   1177 }
   1178 
   1179 void RenderObject::invalidatePaintUsingContainer(const RenderLayerModelObject* paintInvalidationContainer, const LayoutRect& r, InvalidationReason invalidationReason) const
   1180 {
   1181     if (r.isEmpty())
   1182         return;
   1183 
   1184     RELEASE_ASSERT(isRooted());
   1185 
   1186     // FIXME: Unify "devtools.timeline.invalidationTracking" and "blink.invalidation". crbug.com/413527.
   1187     TRACE_EVENT_INSTANT1(TRACE_DISABLED_BY_DEFAULT("devtools.timeline.invalidationTracking"),
   1188         "PaintInvalidationTracking",
   1189         "data", InspectorPaintInvalidationTrackingEvent::data(this, paintInvalidationContainer));
   1190     TRACE_EVENT2(TRACE_DISABLED_BY_DEFAULT("blink.invalidation"), "RenderObject::invalidatePaintUsingContainer()",
   1191         "object", this->debugName().ascii(),
   1192         "info", jsonObjectForPaintInvalidationInfo(r, invalidationReasonToString(invalidationReason)));
   1193 
   1194     if (paintInvalidationContainer->isRenderFlowThread()) {
   1195         toRenderFlowThread(paintInvalidationContainer)->paintInvalidationRectangleInRegions(r);
   1196         return;
   1197     }
   1198 
   1199     if (paintInvalidationContainer->isRenderView()) {
   1200         toRenderView(paintInvalidationContainer)->invalidatePaintForRectangle(r);
   1201         return;
   1202     }
   1203 
   1204     if (paintInvalidationContainer->view()->usesCompositing()) {
   1205         ASSERT(paintInvalidationContainer->isPaintInvalidationContainer());
   1206         paintInvalidationContainer->setBackingNeedsPaintInvalidationInRect(r);
   1207     }
   1208 }
   1209 
   1210 LayoutRect RenderObject::boundsRectForPaintInvalidation(const RenderLayerModelObject* paintInvalidationContainer, const PaintInvalidationState* paintInvalidationState) const
   1211 {
   1212     if (!paintInvalidationContainer)
   1213         return computePaintInvalidationRect(paintInvalidationContainer, paintInvalidationState);
   1214     return RenderLayer::computePaintInvalidationRect(this, paintInvalidationContainer->layer(), paintInvalidationState);
   1215 }
   1216 
   1217 void RenderObject::invalidatePaintRectangle(const LayoutRect& r) const
   1218 {
   1219     RELEASE_ASSERT(isRooted());
   1220 
   1221     if (view()->document().printing())
   1222         return; // Don't invalidate paints if we're printing.
   1223 
   1224     LayoutRect dirtyRect(r);
   1225 
   1226     const RenderLayerModelObject* paintInvalidationContainer = containerForPaintInvalidation();
   1227     RenderLayer::mapRectToPaintInvalidationBacking(this, paintInvalidationContainer, dirtyRect);
   1228     invalidatePaintUsingContainer(paintInvalidationContainer, dirtyRect, InvalidationPaintRectangle);
   1229 }
   1230 
   1231 IntRect RenderObject::pixelSnappedAbsoluteClippedOverflowRect() const
   1232 {
   1233     return pixelSnappedIntRect(absoluteClippedOverflowRect());
   1234 }
   1235 
   1236 const char* RenderObject::invalidationReasonToString(InvalidationReason reason) const
   1237 {
   1238     switch (reason) {
   1239     case InvalidationNone:
   1240         return "none";
   1241     case InvalidationIncremental:
   1242         return "incremental";
   1243     case InvalidationFull:
   1244         return "full";
   1245     case InvalidationBorderFitLines:
   1246         return "border fit lines";
   1247     case InvalidationBorderBoxChange:
   1248         return "border box change";
   1249     case InvalidationBoundsChange:
   1250         return "bounds change";
   1251     case InvalidationLocationChange:
   1252         return "location change";
   1253     case InvalidationBecameVisible:
   1254         return "became visible";
   1255     case InvalidationBecameInvisible:
   1256         return "became invisible";
   1257     case InvalidationScroll:
   1258         return "scroll";
   1259     case InvalidationSelection:
   1260         return "selection";
   1261     case InvalidationLayer:
   1262         return "layer";
   1263     case InvalidationRendererRemoval:
   1264         return "renderer removal";
   1265     case InvalidationPaintRectangle:
   1266         return "invalidate paint rectangle";
   1267     }
   1268     ASSERT_NOT_REACHED();
   1269     return "";
   1270 }
   1271 
   1272 void RenderObject::invalidateTreeIfNeeded(const PaintInvalidationState& paintInvalidationState)
   1273 {
   1274     ASSERT(!needsLayout());
   1275 
   1276     // If we didn't need paint invalidation then our children don't need as well.
   1277     // Skip walking down the tree as everything should be fine below us.
   1278     if (!shouldCheckForPaintInvalidation(paintInvalidationState))
   1279         return;
   1280 
   1281     invalidatePaintIfNeeded(paintInvalidationState, paintInvalidationState.paintInvalidationContainer());
   1282     clearPaintInvalidationState(paintInvalidationState);
   1283     invalidatePaintOfSubtreesIfNeeded(paintInvalidationState);
   1284 }
   1285 
   1286 void RenderObject::invalidatePaintOfSubtreesIfNeeded(const PaintInvalidationState& childPaintInvalidationState)
   1287 {
   1288     for (RenderObject* child = slowFirstChild(); child; child = child->nextSibling()) {
   1289         if (!child->isOutOfFlowPositioned())
   1290             child->invalidateTreeIfNeeded(childPaintInvalidationState);
   1291     }
   1292 }
   1293 
   1294 static PassRefPtr<TraceEvent::ConvertableToTraceFormat> jsonObjectForOldAndNewRects(const LayoutRect& oldRect, const LayoutPoint& oldLocation, const LayoutRect& newRect, const LayoutPoint& newLocation)
   1295 {
   1296     RefPtr<TracedValue> value = TracedValue::create();
   1297     addJsonObjectForRect(value.get(), "oldRect", oldRect);
   1298     addJsonObjectForPoint(value.get(), "oldLocation", oldLocation);
   1299     addJsonObjectForRect(value.get(), "newRect", newRect);
   1300     addJsonObjectForPoint(value.get(), "newLocation", newLocation);
   1301     return value;
   1302 }
   1303 
   1304 InvalidationReason RenderObject::invalidatePaintIfNeeded(const PaintInvalidationState& paintInvalidationState, const RenderLayerModelObject& paintInvalidationContainer)
   1305 {
   1306     RenderView* v = view();
   1307     if (v->document().printing())
   1308         return InvalidationNone; // Don't invalidate paints if we're printing.
   1309 
   1310     const LayoutRect oldBounds = previousPaintInvalidationRect();
   1311     const LayoutPoint oldLocation = previousPositionFromPaintInvalidationBacking();
   1312     const LayoutRect newBounds = boundsRectForPaintInvalidation(&paintInvalidationContainer, &paintInvalidationState);
   1313     const LayoutPoint newLocation = RenderLayer::positionFromPaintInvalidationBacking(this, &paintInvalidationContainer, &paintInvalidationState);
   1314     setPreviousPaintInvalidationRect(newBounds);
   1315     setPreviousPositionFromPaintInvalidationBacking(newLocation);
   1316 
   1317     // If we are set to do a full paint invalidation that means the RenderView will issue
   1318     // paint invalidations. We can then skip issuing of paint invalidations for the child
   1319     // renderers as they'll be covered by the RenderView.
   1320     if (view()->doingFullPaintInvalidation())
   1321         return InvalidationNone;
   1322 
   1323     TRACE_EVENT2(TRACE_DISABLED_BY_DEFAULT("blink.invalidation"), "RenderObject::invalidatePaintIfNeeded()",
   1324         "object", this->debugName().ascii(),
   1325         "info", jsonObjectForOldAndNewRects(oldBounds, oldLocation, newBounds, newLocation));
   1326 
   1327     InvalidationReason invalidationReason = getPaintInvalidationReason(paintInvalidationContainer, oldBounds, oldLocation, newBounds, newLocation);
   1328 
   1329     if (invalidationReason == InvalidationNone)
   1330         return invalidationReason;
   1331 
   1332     if (invalidationReason == InvalidationIncremental) {
   1333         incrementallyInvalidatePaint(paintInvalidationContainer, oldBounds, newBounds, newLocation);
   1334         return invalidationReason;
   1335     }
   1336 
   1337     fullyInvalidatePaint(paintInvalidationContainer, invalidationReason, oldBounds, newBounds);
   1338     return invalidationReason;
   1339 }
   1340 
   1341 InvalidationReason RenderObject::getPaintInvalidationReason(const RenderLayerModelObject& paintInvalidationContainer,
   1342     const LayoutRect& oldBounds, const LayoutPoint& oldPositionFromPaintInvalidationBacking, const LayoutRect& newBounds, const LayoutPoint& newPositionFromPaintInvalidationBacking)
   1343 {
   1344     if (shouldDoFullPaintInvalidation())
   1345         return InvalidationFull;
   1346 
   1347     // Presumably a background or a border exists if border-fit:lines was specified.
   1348     if (style()->borderFit() == BorderFitLines)
   1349         return InvalidationBorderFitLines;
   1350 
   1351     if (compositingState() != PaintsIntoOwnBacking && newPositionFromPaintInvalidationBacking != oldPositionFromPaintInvalidationBacking)
   1352         return InvalidationLocationChange;
   1353 
   1354     // If the bounds are the same then we know that none of the statements below
   1355     // can match, so we can early out since we will not need to do any
   1356     // invalidation.
   1357     if (oldBounds == newBounds)
   1358         return InvalidationNone;
   1359 
   1360     // If we shifted, we don't know the exact reason so we are conservative and trigger a full invalidation. Shifting could
   1361     // be caused by some layout property (left / top) or some in-flow renderer inserted / removed before us in the tree.
   1362     if (newBounds.location() != oldBounds.location())
   1363         return InvalidationBoundsChange;
   1364 
   1365     // This covers the case where we mark containing blocks for layout
   1366     // and they change size but don't have anything to paint. This is
   1367     // a pretty common case for <body> as we add / remove children
   1368     // (and the default background is done by FrameView).
   1369     if (skipInvalidationWhenLaidOutChildren())
   1370         return InvalidationNone;
   1371 
   1372     // If the size is zero on one of our bounds then we know we're going to have
   1373     // to do a full invalidation of either old bounds or new bounds. If we fall
   1374     // into the incremental invalidation we'll issue two invalidations instead
   1375     // of one.
   1376     if (oldBounds.isEmpty())
   1377         return InvalidationBecameVisible;
   1378     if (newBounds.isEmpty())
   1379         return InvalidationBecameInvisible;
   1380 
   1381     return InvalidationIncremental;
   1382 }
   1383 
   1384 void RenderObject::incrementallyInvalidatePaint(const RenderLayerModelObject& paintInvalidationContainer, const LayoutRect& oldBounds, const LayoutRect& newBounds, const LayoutPoint& positionFromPaintInvalidationBacking)
   1385 {
   1386     ASSERT(oldBounds.location() == newBounds.location());
   1387 
   1388     LayoutUnit deltaRight = newBounds.maxX() - oldBounds.maxX();
   1389     if (deltaRight > 0)
   1390         invalidatePaintUsingContainer(&paintInvalidationContainer, LayoutRect(oldBounds.maxX(), newBounds.y(), deltaRight, newBounds.height()), InvalidationIncremental);
   1391     else if (deltaRight < 0)
   1392         invalidatePaintUsingContainer(&paintInvalidationContainer, LayoutRect(newBounds.maxX(), oldBounds.y(), -deltaRight, oldBounds.height()), InvalidationIncremental);
   1393 
   1394     LayoutUnit deltaBottom = newBounds.maxY() - oldBounds.maxY();
   1395     if (deltaBottom > 0)
   1396         invalidatePaintUsingContainer(&paintInvalidationContainer, LayoutRect(newBounds.x(), oldBounds.maxY(), newBounds.width(), deltaBottom), InvalidationIncremental);
   1397     else if (deltaBottom < 0)
   1398         invalidatePaintUsingContainer(&paintInvalidationContainer, LayoutRect(oldBounds.x(), newBounds.maxY(), oldBounds.width(), -deltaBottom), InvalidationIncremental);
   1399 }
   1400 
   1401 void RenderObject::fullyInvalidatePaint(const RenderLayerModelObject& paintInvalidationContainer, InvalidationReason invalidationReason, const LayoutRect& oldBounds, const LayoutRect& newBounds)
   1402 {
   1403     // Otherwise do full paint invalidation.
   1404     invalidatePaintUsingContainer(&paintInvalidationContainer, oldBounds, invalidationReason);
   1405     if (newBounds != oldBounds)
   1406         invalidatePaintUsingContainer(&paintInvalidationContainer, newBounds, invalidationReason);
   1407 }
   1408 
   1409 void RenderObject::invalidatePaintForOverflow()
   1410 {
   1411 }
   1412 
   1413 void RenderObject::invalidatePaintForOverflowIfNeeded()
   1414 {
   1415     if (shouldInvalidateOverflowForPaint())
   1416         invalidatePaintForOverflow();
   1417 }
   1418 
   1419 bool RenderObject::checkForPaintInvalidation() const
   1420 {
   1421     return !document().view()->needsFullPaintInvalidation() && everHadLayout();
   1422 }
   1423 
   1424 LayoutRect RenderObject::rectWithOutlineForPaintInvalidation(const RenderLayerModelObject* paintInvalidationContainer, LayoutUnit outlineWidth, const PaintInvalidationState* paintInvalidationState) const
   1425 {
   1426     LayoutRect r(clippedOverflowRectForPaintInvalidation(paintInvalidationContainer, paintInvalidationState));
   1427     r.inflate(outlineWidth);
   1428     return r;
   1429 }
   1430 
   1431 LayoutRect RenderObject::absoluteClippedOverflowRect() const
   1432 {
   1433     return clippedOverflowRectForPaintInvalidation(view());
   1434 }
   1435 
   1436 LayoutRect RenderObject::clippedOverflowRectForPaintInvalidation(const RenderLayerModelObject*, const PaintInvalidationState*) const
   1437 {
   1438     ASSERT_NOT_REACHED();
   1439     return LayoutRect();
   1440 }
   1441 
   1442 void RenderObject::mapRectToPaintInvalidationBacking(const RenderLayerModelObject* paintInvalidationContainer, LayoutRect& rect, const PaintInvalidationState* paintInvalidationState) const
   1443 {
   1444     if (paintInvalidationContainer == this)
   1445         return;
   1446 
   1447     if (RenderObject* o = parent()) {
   1448         if (o->isRenderBlockFlow()) {
   1449             RenderBlock* cb = toRenderBlock(o);
   1450             if (cb->hasColumns())
   1451                 cb->adjustRectForColumns(rect);
   1452         }
   1453 
   1454         if (o->hasOverflowClip()) {
   1455             RenderBox* boxParent = toRenderBox(o);
   1456             boxParent->applyCachedClipAndScrollOffsetForPaintInvalidation(rect);
   1457             if (rect.isEmpty())
   1458                 return;
   1459         }
   1460 
   1461         o->mapRectToPaintInvalidationBacking(paintInvalidationContainer, rect, paintInvalidationState);
   1462     }
   1463 }
   1464 
   1465 void RenderObject::computeFloatRectForPaintInvalidation(const RenderLayerModelObject*, FloatRect&, const PaintInvalidationState*) const
   1466 {
   1467     ASSERT_NOT_REACHED();
   1468 }
   1469 
   1470 void RenderObject::dirtyLinesFromChangedChild(RenderObject*)
   1471 {
   1472 }
   1473 
   1474 #ifndef NDEBUG
   1475 
   1476 void RenderObject::showTreeForThis() const
   1477 {
   1478     if (node())
   1479         node()->showTreeForThis();
   1480 }
   1481 
   1482 void RenderObject::showRenderTreeForThis() const
   1483 {
   1484     showRenderTree(this, 0);
   1485 }
   1486 
   1487 void RenderObject::showLineTreeForThis() const
   1488 {
   1489     if (containingBlock())
   1490         containingBlock()->showLineTreeAndMark(0, 0, 0, 0, this);
   1491 }
   1492 
   1493 void RenderObject::showRenderObject() const
   1494 {
   1495     showRenderObject(0);
   1496 }
   1497 
   1498 void RenderObject::showRenderObject(int printedCharacters) const
   1499 {
   1500     printedCharacters += fprintf(stderr, "%s %p", renderName(), this);
   1501 
   1502     if (node()) {
   1503         if (printedCharacters)
   1504             for (; printedCharacters < showTreeCharacterOffset; printedCharacters++)
   1505                 fputc(' ', stderr);
   1506         fputc('\t', stderr);
   1507         node()->showNode();
   1508     } else
   1509         fputc('\n', stderr);
   1510 }
   1511 
   1512 void RenderObject::showRenderTreeAndMark(const RenderObject* markedObject1, const char* markedLabel1, const RenderObject* markedObject2, const char* markedLabel2, int depth) const
   1513 {
   1514     int printedCharacters = 0;
   1515     if (markedObject1 == this && markedLabel1)
   1516         printedCharacters += fprintf(stderr, "%s", markedLabel1);
   1517     if (markedObject2 == this && markedLabel2)
   1518         printedCharacters += fprintf(stderr, "%s", markedLabel2);
   1519     for (; printedCharacters < depth * 2; printedCharacters++)
   1520         fputc(' ', stderr);
   1521 
   1522     showRenderObject(printedCharacters);
   1523 
   1524     for (const RenderObject* child = slowFirstChild(); child; child = child->nextSibling())
   1525         child->showRenderTreeAndMark(markedObject1, markedLabel1, markedObject2, markedLabel2, depth + 1);
   1526 }
   1527 
   1528 #endif // NDEBUG
   1529 
   1530 bool RenderObject::isSelectable() const
   1531 {
   1532     return !isInert() && !(style()->userSelect() == SELECT_NONE && style()->userModify() == READ_ONLY);
   1533 }
   1534 
   1535 Color RenderObject::selectionBackgroundColor() const
   1536 {
   1537     if (!isSelectable())
   1538         return Color::transparent;
   1539 
   1540     if (RefPtr<RenderStyle> pseudoStyle = getUncachedPseudoStyleFromParentOrShadowHost())
   1541         return resolveColor(pseudoStyle.get(), CSSPropertyBackgroundColor).blendWithWhite();
   1542     return frame()->selection().isFocusedAndActive() ?
   1543         RenderTheme::theme().activeSelectionBackgroundColor() :
   1544         RenderTheme::theme().inactiveSelectionBackgroundColor();
   1545 }
   1546 
   1547 Color RenderObject::selectionColor(int colorProperty) const
   1548 {
   1549     // If the element is unselectable, or we are only painting the selection,
   1550     // don't override the foreground color with the selection foreground color.
   1551     if (!isSelectable() || (frame()->view()->paintBehavior() & PaintBehaviorSelectionOnly))
   1552         return resolveColor(colorProperty);
   1553 
   1554     if (RefPtr<RenderStyle> pseudoStyle = getUncachedPseudoStyleFromParentOrShadowHost())
   1555         return resolveColor(pseudoStyle.get(), colorProperty);
   1556     if (!RenderTheme::theme().supportsSelectionForegroundColors())
   1557         return resolveColor(colorProperty);
   1558     return frame()->selection().isFocusedAndActive() ?
   1559         RenderTheme::theme().activeSelectionForegroundColor() :
   1560         RenderTheme::theme().inactiveSelectionForegroundColor();
   1561 }
   1562 
   1563 Color RenderObject::selectionForegroundColor() const
   1564 {
   1565     return selectionColor(CSSPropertyWebkitTextFillColor);
   1566 }
   1567 
   1568 Color RenderObject::selectionEmphasisMarkColor() const
   1569 {
   1570     return selectionColor(CSSPropertyWebkitTextEmphasisColor);
   1571 }
   1572 
   1573 void RenderObject::selectionStartEnd(int& spos, int& epos) const
   1574 {
   1575     view()->selectionStartEnd(spos, epos);
   1576 }
   1577 
   1578 void RenderObject::handleDynamicFloatPositionChange()
   1579 {
   1580     // We have gone from not affecting the inline status of the parent flow to suddenly
   1581     // having an impact.  See if there is a mismatch between the parent flow's
   1582     // childrenInline() state and our state.
   1583     setInline(style()->isDisplayInlineType());
   1584     if (isInline() != parent()->childrenInline()) {
   1585         if (!isInline())
   1586             toRenderBoxModelObject(parent())->childBecameNonInline(this);
   1587         else {
   1588             // An anonymous block must be made to wrap this inline.
   1589             RenderBlock* block = toRenderBlock(parent())->createAnonymousBlock();
   1590             RenderObjectChildList* childlist = parent()->virtualChildren();
   1591             childlist->insertChildNode(parent(), block, this);
   1592             block->children()->appendChildNode(block, childlist->removeChildNode(parent(), this));
   1593         }
   1594     }
   1595 }
   1596 
   1597 StyleDifference RenderObject::adjustStyleDifference(StyleDifference diff) const
   1598 {
   1599     if (diff.transformChanged() && isSVG())
   1600         diff.setNeedsFullLayout();
   1601 
   1602     // If transform changed, and the layer does not paint into its own separate backing, then we need to invalidate paints.
   1603     if (diff.transformChanged()) {
   1604         // Text nodes share style with their parents but transforms don't apply to them,
   1605         // hence the !isText() check.
   1606         if (!isText() && (!hasLayer() || !toRenderLayerModelObject(this)->layer()->hasStyleDeterminedDirectCompositingReasons()))
   1607             diff.setNeedsPaintInvalidationLayer();
   1608     }
   1609 
   1610     // If opacity or zIndex changed, and the layer does not paint into its own separate backing, then we need to invalidate paints (also
   1611     // ignoring text nodes)
   1612     if (diff.opacityChanged() || diff.zIndexChanged()) {
   1613         if (!isText() && (!hasLayer() || !toRenderLayerModelObject(this)->layer()->hasStyleDeterminedDirectCompositingReasons()))
   1614             diff.setNeedsPaintInvalidationLayer();
   1615     }
   1616 
   1617     // If filter changed, and the layer does not paint into its own separate backing or it paints with filters, then we need to invalidate paints.
   1618     if (diff.filterChanged() && hasLayer()) {
   1619         RenderLayer* layer = toRenderLayerModelObject(this)->layer();
   1620         if (!layer->hasStyleDeterminedDirectCompositingReasons() || layer->paintsWithFilters())
   1621             diff.setNeedsPaintInvalidationLayer();
   1622     }
   1623 
   1624     if (diff.textOrColorChanged() && !diff.needsPaintInvalidation()
   1625         && hasImmediateNonWhitespaceTextChildOrPropertiesDependentOnColor())
   1626         diff.setNeedsPaintInvalidationObject();
   1627 
   1628     // The answer to layerTypeRequired() for plugins, iframes, and canvas can change without the actual
   1629     // style changing, since it depends on whether we decide to composite these elements. When the
   1630     // layer status of one of these elements changes, we need to force a layout.
   1631     if (!diff.needsFullLayout() && style() && isLayerModelObject()) {
   1632         bool requiresLayer = toRenderLayerModelObject(this)->layerTypeRequired() != NoLayer;
   1633         if (hasLayer() != requiresLayer)
   1634             diff.setNeedsFullLayout();
   1635     }
   1636 
   1637     // If we have no layer(), just treat a PaintInvalidationLayer hint as a normal paint invalidation.
   1638     if (diff.needsPaintInvalidationLayer() && !hasLayer()) {
   1639         diff.clearNeedsPaintInvalidation();
   1640         diff.setNeedsPaintInvalidationObject();
   1641     }
   1642 
   1643     return diff;
   1644 }
   1645 
   1646 void RenderObject::setPseudoStyle(PassRefPtr<RenderStyle> pseudoStyle)
   1647 {
   1648     ASSERT(pseudoStyle->styleType() == BEFORE || pseudoStyle->styleType() == AFTER);
   1649 
   1650     // FIXME: We should consider just making all pseudo items use an inherited style.
   1651 
   1652     // Images are special and must inherit the pseudoStyle so the width and height of
   1653     // the pseudo element doesn't change the size of the image. In all other cases we
   1654     // can just share the style.
   1655     //
   1656     // Quotes are also RenderInline, so we need to create an inherited style to avoid
   1657     // getting an inline with positioning or an invalid display.
   1658     //
   1659     if (isImage() || isQuote()) {
   1660         RefPtr<RenderStyle> style = RenderStyle::create();
   1661         style->inheritFrom(pseudoStyle.get());
   1662         setStyle(style.release());
   1663         return;
   1664     }
   1665 
   1666     setStyle(pseudoStyle);
   1667 }
   1668 
   1669 inline bool RenderObject::hasImmediateNonWhitespaceTextChildOrPropertiesDependentOnColor() const
   1670 {
   1671     if (style()->hasBorder() || style()->hasOutline())
   1672         return true;
   1673     for (const RenderObject* r = slowFirstChild(); r; r = r->nextSibling()) {
   1674         if (r->isText() && !toRenderText(r)->isAllCollapsibleWhitespace())
   1675             return true;
   1676         if (r->style()->hasOutline() || r->style()->hasBorder())
   1677             return true;
   1678     }
   1679     return false;
   1680 }
   1681 
   1682 void RenderObject::markContainingBlocksForOverflowRecalc()
   1683 {
   1684     for (RenderBlock* container = containingBlock(); container && !container->childNeedsOverflowRecalcAfterStyleChange(); container = container->containingBlock())
   1685         container->setChildNeedsOverflowRecalcAfterStyleChange(true);
   1686 }
   1687 
   1688 void RenderObject::setNeedsOverflowRecalcAfterStyleChange()
   1689 {
   1690     bool neededRecalc = needsOverflowRecalcAfterStyleChange();
   1691     setSelfNeedsOverflowRecalcAfterStyleChange(true);
   1692     if (!neededRecalc)
   1693         markContainingBlocksForOverflowRecalc();
   1694 }
   1695 
   1696 void RenderObject::setStyle(PassRefPtr<RenderStyle> style)
   1697 {
   1698     ASSERT(style);
   1699 
   1700     if (m_style == style) {
   1701         // We need to run through adjustStyleDifference() for iframes, plugins, and canvas so
   1702         // style sharing is disabled for them. That should ensure that we never hit this code path.
   1703         ASSERT(!isRenderIFrame() && !isEmbeddedObject() && !isCanvas());
   1704         return;
   1705     }
   1706 
   1707     StyleDifference diff;
   1708     if (m_style)
   1709         diff = m_style->visualInvalidationDiff(*style);
   1710 
   1711     diff = adjustStyleDifference(diff);
   1712 
   1713     styleWillChange(diff, *style);
   1714 
   1715     RefPtr<RenderStyle> oldStyle = m_style.release();
   1716     setStyleInternal(style);
   1717 
   1718     updateFillImages(oldStyle ? &oldStyle->backgroundLayers() : 0, m_style->backgroundLayers());
   1719     updateFillImages(oldStyle ? &oldStyle->maskLayers() : 0, m_style->maskLayers());
   1720 
   1721     updateImage(oldStyle ? oldStyle->borderImage().image() : 0, m_style->borderImage().image());
   1722     updateImage(oldStyle ? oldStyle->maskBoxImage().image() : 0, m_style->maskBoxImage().image());
   1723 
   1724     updateShapeImage(oldStyle ? oldStyle->shapeOutside() : 0, m_style->shapeOutside());
   1725 
   1726     bool doesNotNeedLayout = !m_parent || isText();
   1727 
   1728     styleDidChange(diff, oldStyle.get());
   1729 
   1730     // FIXME: |this| might be destroyed here. This can currently happen for a RenderTextFragment when
   1731     // its first-letter block gets an update in RenderTextFragment::styleDidChange. For RenderTextFragment(s),
   1732     // we will safely bail out with the doesNotNeedLayout flag. We might want to broaden this condition
   1733     // in the future as we move renderer changes out of layout and into style changes.
   1734     if (doesNotNeedLayout)
   1735         return;
   1736 
   1737     // Now that the layer (if any) has been updated, we need to adjust the diff again,
   1738     // check whether we should layout now, and decide if we need to invalidate paints.
   1739     StyleDifference updatedDiff = adjustStyleDifference(diff);
   1740 
   1741     if (!diff.needsFullLayout()) {
   1742         if (updatedDiff.needsFullLayout())
   1743             setNeedsLayoutAndPrefWidthsRecalc();
   1744         else if (updatedDiff.needsPositionedMovementLayout())
   1745             setNeedsPositionedMovementLayout();
   1746     }
   1747 
   1748     if (diff.transformChanged() && !needsLayout()) {
   1749         if (RenderBlock* container = containingBlock())
   1750             container->setNeedsOverflowRecalcAfterStyleChange();
   1751     }
   1752 
   1753     if (updatedDiff.needsPaintInvalidationLayer())
   1754         toRenderLayerModelObject(this)->layer()->setShouldDoFullPaintInvalidationIncludingNonCompositingDescendants();
   1755     else if (diff.needsPaintInvalidationObject() || updatedDiff.needsPaintInvalidationObject())
   1756         setShouldDoFullPaintInvalidation(true);
   1757 }
   1758 
   1759 static inline bool rendererHasBackground(const RenderObject* renderer)
   1760 {
   1761     return renderer && renderer->hasBackground();
   1762 }
   1763 
   1764 void RenderObject::styleWillChange(StyleDifference diff, const RenderStyle& newStyle)
   1765 {
   1766     if (m_style) {
   1767         // If our z-index changes value or our visibility changes,
   1768         // we need to dirty our stacking context's z-order list.
   1769         bool visibilityChanged = m_style->visibility() != newStyle.visibility()
   1770             || m_style->zIndex() != newStyle.zIndex()
   1771             || m_style->hasAutoZIndex() != newStyle.hasAutoZIndex();
   1772         if (visibilityChanged) {
   1773             document().setAnnotatedRegionsDirty(true);
   1774             if (AXObjectCache* cache = document().existingAXObjectCache())
   1775                 cache->childrenChanged(parent());
   1776         }
   1777 
   1778         // Keep layer hierarchy visibility bits up to date if visibility changes.
   1779         if (m_style->visibility() != newStyle.visibility()) {
   1780             // We might not have an enclosing layer yet because we might not be in the tree.
   1781             if (RenderLayer* layer = enclosingLayer())
   1782                 layer->potentiallyDirtyVisibleContentStatus(newStyle.visibility());
   1783         }
   1784 
   1785         if (isFloating() && (m_style->floating() != newStyle.floating()))
   1786             // For changes in float styles, we need to conceivably remove ourselves
   1787             // from the floating objects list.
   1788             toRenderBox(this)->removeFloatingOrPositionedChildFromBlockLists();
   1789         else if (isOutOfFlowPositioned() && (m_style->position() != newStyle.position()))
   1790             // For changes in positioning styles, we need to conceivably remove ourselves
   1791             // from the positioned objects list.
   1792             toRenderBox(this)->removeFloatingOrPositionedChildFromBlockLists();
   1793 
   1794         s_affectsParentBlock = isFloatingOrOutOfFlowPositioned()
   1795             && (!newStyle.isFloating() && !newStyle.hasOutOfFlowPosition())
   1796             && parent() && (parent()->isRenderBlockFlow() || parent()->isRenderInline());
   1797 
   1798         // Clearing these bits is required to avoid leaving stale renderers.
   1799         // FIXME: We shouldn't need that hack if our logic was totally correct.
   1800         if (diff.needsLayout()) {
   1801             setFloating(false);
   1802             clearPositionedState();
   1803         }
   1804     } else {
   1805         s_affectsParentBlock = false;
   1806     }
   1807 
   1808     if (view()->frameView()) {
   1809         bool shouldBlitOnFixedBackgroundImage = false;
   1810         if (RuntimeEnabledFeatures::fastMobileScrollingEnabled()) {
   1811             // On low-powered/mobile devices, preventing blitting on a scroll can cause noticeable delays
   1812             // when scrolling a page with a fixed background image. As an optimization, assuming there are
   1813             // no fixed positoned elements on the page, we can acclerate scrolling (via blitting) if we
   1814             // ignore the CSS property "background-attachment: fixed".
   1815             shouldBlitOnFixedBackgroundImage = true;
   1816         }
   1817         bool newStyleSlowScroll = !shouldBlitOnFixedBackgroundImage && newStyle.hasFixedBackgroundImage();
   1818         bool oldStyleSlowScroll = m_style && !shouldBlitOnFixedBackgroundImage && m_style->hasFixedBackgroundImage();
   1819 
   1820         bool drawsRootBackground = isDocumentElement() || (isBody() && !rendererHasBackground(document().documentElement()->renderer()));
   1821         if (drawsRootBackground && !shouldBlitOnFixedBackgroundImage) {
   1822             if (view()->compositor()->supportsFixedRootBackgroundCompositing()) {
   1823                 if (newStyleSlowScroll && newStyle.hasEntirelyFixedBackground())
   1824                     newStyleSlowScroll = false;
   1825 
   1826                 if (oldStyleSlowScroll && m_style->hasEntirelyFixedBackground())
   1827                     oldStyleSlowScroll = false;
   1828             }
   1829         }
   1830 
   1831         if (oldStyleSlowScroll != newStyleSlowScroll) {
   1832             if (oldStyleSlowScroll)
   1833                 view()->frameView()->removeSlowRepaintObject();
   1834             if (newStyleSlowScroll)
   1835                 view()->frameView()->addSlowRepaintObject();
   1836         }
   1837     }
   1838 
   1839     // Elements with non-auto touch-action will send a SetTouchAction message
   1840     // on touchstart in EventHandler::handleTouchEvent, and so effectively have
   1841     // a touchstart handler that must be reported.
   1842     //
   1843     // Since a CSS property cannot be applied directly to a text node, a
   1844     // handler will have already been added for its parent so ignore it.
   1845     TouchAction oldTouchAction = m_style ? m_style->touchAction() : TouchActionAuto;
   1846     if (node() && !node()->isTextNode() && (oldTouchAction == TouchActionAuto) != (newStyle.touchAction() == TouchActionAuto)) {
   1847         EventHandlerRegistry& registry = document().frameHost()->eventHandlerRegistry();
   1848         if (newStyle.touchAction() != TouchActionAuto)
   1849             registry.didAddEventHandler(*node(), EventHandlerRegistry::TouchEvent);
   1850         else
   1851             registry.didRemoveEventHandler(*node(), EventHandlerRegistry::TouchEvent);
   1852     }
   1853 }
   1854 
   1855 static bool areNonIdenticalCursorListsEqual(const RenderStyle* a, const RenderStyle* b)
   1856 {
   1857     ASSERT(a->cursors() != b->cursors());
   1858     return a->cursors() && b->cursors() && *a->cursors() == *b->cursors();
   1859 }
   1860 
   1861 static inline bool areCursorsEqual(const RenderStyle* a, const RenderStyle* b)
   1862 {
   1863     return a->cursor() == b->cursor() && (a->cursors() == b->cursors() || areNonIdenticalCursorListsEqual(a, b));
   1864 }
   1865 
   1866 void RenderObject::styleDidChange(StyleDifference diff, const RenderStyle* oldStyle)
   1867 {
   1868     if (s_affectsParentBlock)
   1869         handleDynamicFloatPositionChange();
   1870 
   1871     if (!m_parent)
   1872         return;
   1873 
   1874     if (diff.needsFullLayout()) {
   1875         RenderCounter::rendererStyleChanged(*this, oldStyle, m_style.get());
   1876 
   1877         // If the object already needs layout, then setNeedsLayout won't do
   1878         // any work. But if the containing block has changed, then we may need
   1879         // to mark the new containing blocks for layout. The change that can
   1880         // directly affect the containing block of this object is a change to
   1881         // the position style.
   1882         if (needsLayout() && oldStyle->position() != m_style->position())
   1883             markContainingBlocksForLayout();
   1884 
   1885         // Ditto.
   1886         if (needsOverflowRecalcAfterStyleChange() && oldStyle->position() != m_style->position())
   1887             markContainingBlocksForOverflowRecalc();
   1888 
   1889         if (diff.needsFullLayout())
   1890             setNeedsLayoutAndPrefWidthsRecalc();
   1891     } else if (diff.needsPositionedMovementLayout())
   1892         setNeedsPositionedMovementLayout();
   1893 
   1894     // Don't check for paint invalidation here; we need to wait until the layer has been
   1895     // updated by subclasses before we know if we have to invalidate paints (in setStyle()).
   1896 
   1897     if (oldStyle && !areCursorsEqual(oldStyle, style())) {
   1898         if (LocalFrame* frame = this->frame())
   1899             frame->eventHandler().scheduleCursorUpdate();
   1900     }
   1901 }
   1902 
   1903 void RenderObject::propagateStyleToAnonymousChildren(bool blockChildrenOnly)
   1904 {
   1905     // FIXME: We could save this call when the change only affected non-inherited properties.
   1906     for (RenderObject* child = slowFirstChild(); child; child = child->nextSibling()) {
   1907         if (!child->isAnonymous() || child->style()->styleType() != NOPSEUDO)
   1908             continue;
   1909 
   1910         if (blockChildrenOnly && !child->isRenderBlock())
   1911             continue;
   1912 
   1913         if (child->isRenderFullScreen() || child->isRenderFullScreenPlaceholder())
   1914             continue;
   1915 
   1916         RefPtr<RenderStyle> newStyle = RenderStyle::createAnonymousStyleWithDisplay(style(), child->style()->display());
   1917         if (!document().regionBasedColumnsEnabled()) {
   1918             if (style()->specifiesColumns()) {
   1919                 if (child->style()->specifiesColumns())
   1920                     newStyle->inheritColumnPropertiesFrom(style());
   1921                 if (child->style()->columnSpan())
   1922                     newStyle->setColumnSpan(ColumnSpanAll);
   1923             }
   1924         }
   1925 
   1926         // Preserve the position style of anonymous block continuations as they can have relative position when
   1927         // they contain block descendants of relative positioned inlines.
   1928         if (child->isRelPositioned() && toRenderBlock(child)->isAnonymousBlockContinuation())
   1929             newStyle->setPosition(child->style()->position());
   1930 
   1931         updateAnonymousChildStyle(child, newStyle.get());
   1932 
   1933         child->setStyle(newStyle.release());
   1934     }
   1935 }
   1936 
   1937 void RenderObject::updateFillImages(const FillLayer* oldLayers, const FillLayer& newLayers)
   1938 {
   1939     // Optimize the common case
   1940     if (oldLayers && !oldLayers->next() && !newLayers.next() && (oldLayers->image() == newLayers.image()))
   1941         return;
   1942 
   1943     // Go through the new layers and addClients first, to avoid removing all clients of an image.
   1944     for (const FillLayer* currNew = &newLayers; currNew; currNew = currNew->next()) {
   1945         if (currNew->image())
   1946             currNew->image()->addClient(this);
   1947     }
   1948 
   1949     for (const FillLayer* currOld = oldLayers; currOld; currOld = currOld->next()) {
   1950         if (currOld->image())
   1951             currOld->image()->removeClient(this);
   1952     }
   1953 }
   1954 
   1955 void RenderObject::updateImage(StyleImage* oldImage, StyleImage* newImage)
   1956 {
   1957     if (oldImage != newImage) {
   1958         if (oldImage)
   1959             oldImage->removeClient(this);
   1960         if (newImage)
   1961             newImage->addClient(this);
   1962     }
   1963 }
   1964 
   1965 void RenderObject::updateShapeImage(const ShapeValue* oldShapeValue, const ShapeValue* newShapeValue)
   1966 {
   1967     if (oldShapeValue || newShapeValue)
   1968         updateImage(oldShapeValue ? oldShapeValue->image() : 0, newShapeValue ? newShapeValue->image() : 0);
   1969 }
   1970 
   1971 LayoutRect RenderObject::viewRect() const
   1972 {
   1973     return view()->viewRect();
   1974 }
   1975 
   1976 FloatPoint RenderObject::localToAbsolute(const FloatPoint& localPoint, MapCoordinatesFlags mode) const
   1977 {
   1978     TransformState transformState(TransformState::ApplyTransformDirection, localPoint);
   1979     mapLocalToContainer(0, transformState, mode | ApplyContainerFlip);
   1980     transformState.flatten();
   1981 
   1982     return transformState.lastPlanarPoint();
   1983 }
   1984 
   1985 FloatPoint RenderObject::absoluteToLocal(const FloatPoint& containerPoint, MapCoordinatesFlags mode) const
   1986 {
   1987     TransformState transformState(TransformState::UnapplyInverseTransformDirection, containerPoint);
   1988     mapAbsoluteToLocalPoint(mode, transformState);
   1989     transformState.flatten();
   1990 
   1991     return transformState.lastPlanarPoint();
   1992 }
   1993 
   1994 FloatQuad RenderObject::absoluteToLocalQuad(const FloatQuad& quad, MapCoordinatesFlags mode) const
   1995 {
   1996     TransformState transformState(TransformState::UnapplyInverseTransformDirection, quad.boundingBox().center(), quad);
   1997     mapAbsoluteToLocalPoint(mode, transformState);
   1998     transformState.flatten();
   1999     return transformState.lastPlanarQuad();
   2000 }
   2001 
   2002 void RenderObject::mapLocalToContainer(const RenderLayerModelObject* paintInvalidationContainer, TransformState& transformState, MapCoordinatesFlags mode, bool* wasFixed, const PaintInvalidationState* paintInvalidationState) const
   2003 {
   2004     if (paintInvalidationContainer == this)
   2005         return;
   2006 
   2007     RenderObject* o = parent();
   2008     if (!o)
   2009         return;
   2010 
   2011     // FIXME: this should call offsetFromContainer to share code, but I'm not sure it's ever called.
   2012     LayoutPoint centerPoint = roundedLayoutPoint(transformState.mappedPoint());
   2013     if (mode & ApplyContainerFlip && o->isBox()) {
   2014         if (o->style()->isFlippedBlocksWritingMode())
   2015             transformState.move(toRenderBox(o)->flipForWritingModeIncludingColumns(roundedLayoutPoint(transformState.mappedPoint())) - centerPoint);
   2016         mode &= ~ApplyContainerFlip;
   2017     }
   2018 
   2019     transformState.move(o->columnOffset(roundedLayoutPoint(transformState.mappedPoint())));
   2020 
   2021     if (o->hasOverflowClip())
   2022         transformState.move(-toRenderBox(o)->scrolledContentOffset());
   2023 
   2024     o->mapLocalToContainer(paintInvalidationContainer, transformState, mode, wasFixed, paintInvalidationState);
   2025 }
   2026 
   2027 const RenderObject* RenderObject::pushMappingToContainer(const RenderLayerModelObject* ancestorToStopAt, RenderGeometryMap& geometryMap) const
   2028 {
   2029     ASSERT_UNUSED(ancestorToStopAt, ancestorToStopAt != this);
   2030 
   2031     RenderObject* container = parent();
   2032     if (!container)
   2033         return 0;
   2034 
   2035     // FIXME: this should call offsetFromContainer to share code, but I'm not sure it's ever called.
   2036     LayoutSize offset;
   2037     if (container->hasOverflowClip())
   2038         offset = -toRenderBox(container)->scrolledContentOffset();
   2039 
   2040     geometryMap.push(this, offset, hasColumns());
   2041 
   2042     return container;
   2043 }
   2044 
   2045 void RenderObject::mapAbsoluteToLocalPoint(MapCoordinatesFlags mode, TransformState& transformState) const
   2046 {
   2047     RenderObject* o = parent();
   2048     if (o) {
   2049         o->mapAbsoluteToLocalPoint(mode, transformState);
   2050         if (o->hasOverflowClip())
   2051             transformState.move(toRenderBox(o)->scrolledContentOffset());
   2052     }
   2053 }
   2054 
   2055 bool RenderObject::shouldUseTransformFromContainer(const RenderObject* containerObject) const
   2056 {
   2057     // hasTransform() indicates whether the object has transform, transform-style or perspective. We just care about transform,
   2058     // so check the layer's transform directly.
   2059     return (hasLayer() && toRenderLayerModelObject(this)->layer()->transform()) || (containerObject && containerObject->style()->hasPerspective());
   2060 }
   2061 
   2062 void RenderObject::getTransformFromContainer(const RenderObject* containerObject, const LayoutSize& offsetInContainer, TransformationMatrix& transform) const
   2063 {
   2064     transform.makeIdentity();
   2065     transform.translate(offsetInContainer.width().toFloat(), offsetInContainer.height().toFloat());
   2066     RenderLayer* layer = hasLayer() ? toRenderLayerModelObject(this)->layer() : 0;
   2067     if (layer && layer->transform())
   2068         transform.multiply(layer->currentTransform());
   2069 
   2070     if (containerObject && containerObject->hasLayer() && containerObject->style()->hasPerspective()) {
   2071         // Perpsective on the container affects us, so we have to factor it in here.
   2072         ASSERT(containerObject->hasLayer());
   2073         FloatPoint perspectiveOrigin = toRenderLayerModelObject(containerObject)->layer()->perspectiveOrigin();
   2074 
   2075         TransformationMatrix perspectiveMatrix;
   2076         perspectiveMatrix.applyPerspective(containerObject->style()->perspective());
   2077 
   2078         transform.translateRight3d(-perspectiveOrigin.x(), -perspectiveOrigin.y(), 0);
   2079         transform = perspectiveMatrix * transform;
   2080         transform.translateRight3d(perspectiveOrigin.x(), perspectiveOrigin.y(), 0);
   2081     }
   2082 }
   2083 
   2084 FloatQuad RenderObject::localToContainerQuad(const FloatQuad& localQuad, const RenderLayerModelObject* paintInvalidationContainer, MapCoordinatesFlags mode, bool* wasFixed) const
   2085 {
   2086     // Track the point at the center of the quad's bounding box. As mapLocalToContainer() calls offsetFromContainer(),
   2087     // it will use that point as the reference point to decide which column's transform to apply in multiple-column blocks.
   2088     TransformState transformState(TransformState::ApplyTransformDirection, localQuad.boundingBox().center(), localQuad);
   2089     mapLocalToContainer(paintInvalidationContainer, transformState, mode | ApplyContainerFlip | UseTransforms, wasFixed);
   2090     transformState.flatten();
   2091 
   2092     return transformState.lastPlanarQuad();
   2093 }
   2094 
   2095 FloatPoint RenderObject::localToContainerPoint(const FloatPoint& localPoint, const RenderLayerModelObject* paintInvalidationContainer, MapCoordinatesFlags mode, bool* wasFixed, const PaintInvalidationState* paintInvalidationState) const
   2096 {
   2097     TransformState transformState(TransformState::ApplyTransformDirection, localPoint);
   2098     mapLocalToContainer(paintInvalidationContainer, transformState, mode | ApplyContainerFlip | UseTransforms, wasFixed, paintInvalidationState);
   2099     transformState.flatten();
   2100 
   2101     return transformState.lastPlanarPoint();
   2102 }
   2103 
   2104 FloatPoint RenderObject::localToInvalidationBackingPoint(const LayoutPoint& localPoint, RenderLayer** backingLayer)
   2105 {
   2106     const RenderLayerModelObject* paintInvalidationContainer = containerForPaintInvalidation();
   2107     ASSERT(paintInvalidationContainer);
   2108     RenderLayer* layer = paintInvalidationContainer->layer();
   2109     ASSERT(layer);
   2110 
   2111     if (backingLayer)
   2112         *backingLayer = layer;
   2113     FloatPoint containerPoint = localToContainerPoint(localPoint, paintInvalidationContainer, TraverseDocumentBoundaries);
   2114 
   2115     if (layer->compositingState() == NotComposited) // This can happen for RenderFlowThread.
   2116         return containerPoint;
   2117 
   2118     RenderLayer::mapPointToPaintBackingCoordinates(paintInvalidationContainer, containerPoint);
   2119     return containerPoint;
   2120 }
   2121 
   2122 
   2123 LayoutSize RenderObject::offsetFromContainer(const RenderObject* o, const LayoutPoint& point, bool* offsetDependsOnPoint) const
   2124 {
   2125     ASSERT(o == container());
   2126 
   2127     LayoutSize offset = o->columnOffset(point);
   2128 
   2129     if (o->hasOverflowClip())
   2130         offset -= toRenderBox(o)->scrolledContentOffset();
   2131 
   2132     if (offsetDependsOnPoint)
   2133         *offsetDependsOnPoint = hasColumns() || o->isRenderFlowThread();
   2134 
   2135     return offset;
   2136 }
   2137 
   2138 LayoutSize RenderObject::offsetFromAncestorContainer(const RenderObject* container) const
   2139 {
   2140     LayoutSize offset;
   2141     LayoutPoint referencePoint;
   2142     const RenderObject* currContainer = this;
   2143     do {
   2144         const RenderObject* nextContainer = currContainer->container();
   2145         ASSERT(nextContainer);  // This means we reached the top without finding container.
   2146         if (!nextContainer)
   2147             break;
   2148         ASSERT(!currContainer->hasTransform());
   2149         LayoutSize currentOffset = currContainer->offsetFromContainer(nextContainer, referencePoint);
   2150         offset += currentOffset;
   2151         referencePoint.move(currentOffset);
   2152         currContainer = nextContainer;
   2153     } while (currContainer != container);
   2154 
   2155     return offset;
   2156 }
   2157 
   2158 LayoutRect RenderObject::localCaretRect(InlineBox*, int, LayoutUnit* extraWidthToEndOfLine)
   2159 {
   2160     if (extraWidthToEndOfLine)
   2161         *extraWidthToEndOfLine = 0;
   2162 
   2163     return LayoutRect();
   2164 }
   2165 
   2166 void RenderObject::computeLayerHitTestRects(LayerHitTestRects& layerRects) const
   2167 {
   2168     // Figure out what layer our container is in. Any offset (or new layer) for this
   2169     // renderer within it's container will be applied in addLayerHitTestRects.
   2170     LayoutPoint layerOffset;
   2171     const RenderLayer* currentLayer = 0;
   2172 
   2173     if (!hasLayer()) {
   2174         RenderObject* container = this->container();
   2175         currentLayer = container->enclosingLayer();
   2176         if (container && currentLayer->renderer() != container) {
   2177             layerOffset.move(container->offsetFromAncestorContainer(currentLayer->renderer()));
   2178             // If the layer itself is scrolled, we have to undo the subtraction of its scroll
   2179             // offset since we want the offset relative to the scrolling content, not the
   2180             // element itself.
   2181             if (currentLayer->renderer()->hasOverflowClip())
   2182                 layerOffset.move(currentLayer->renderBox()->scrolledContentOffset());
   2183         }
   2184     }
   2185 
   2186     this->addLayerHitTestRects(layerRects, currentLayer, layerOffset, LayoutRect());
   2187 }
   2188 
   2189 void RenderObject::addLayerHitTestRects(LayerHitTestRects& layerRects, const RenderLayer* currentLayer, const LayoutPoint& layerOffset, const LayoutRect& containerRect) const
   2190 {
   2191     ASSERT(currentLayer);
   2192     ASSERT(currentLayer == this->enclosingLayer());
   2193 
   2194     // Compute the rects for this renderer only and add them to the results.
   2195     // Note that we could avoid passing the offset and instead adjust each result, but this
   2196     // seems slightly simpler.
   2197     Vector<LayoutRect> ownRects;
   2198     LayoutRect newContainerRect;
   2199     computeSelfHitTestRects(ownRects, layerOffset);
   2200 
   2201     // When we get to have a lot of rects on a layer, the performance cost of tracking those
   2202     // rects outweighs the benefit of doing compositor thread hit testing.
   2203     // FIXME: This limit needs to be low due to the O(n^2) algorithm in
   2204     // WebLayer::setTouchEventHandlerRegion - crbug.com/300282.
   2205     const size_t maxRectsPerLayer = 100;
   2206 
   2207     LayerHitTestRects::iterator iter = layerRects.find(currentLayer);
   2208     Vector<LayoutRect>* iterValue;
   2209     if (iter == layerRects.end())
   2210         iterValue = &layerRects.add(currentLayer, Vector<LayoutRect>()).storedValue->value;
   2211     else
   2212         iterValue = &iter->value;
   2213     for (size_t i = 0; i < ownRects.size(); i++) {
   2214         if (!containerRect.contains(ownRects[i])) {
   2215             iterValue->append(ownRects[i]);
   2216             if (iterValue->size() > maxRectsPerLayer) {
   2217                 // Just mark the entire layer instead, and switch to walking the layer
   2218                 // tree instead of the render tree.
   2219                 layerRects.remove(currentLayer);
   2220                 currentLayer->addLayerHitTestRects(layerRects);
   2221                 return;
   2222             }
   2223             if (newContainerRect.isEmpty())
   2224                 newContainerRect = ownRects[i];
   2225         }
   2226     }
   2227     if (newContainerRect.isEmpty())
   2228         newContainerRect = containerRect;
   2229 
   2230     // If it's possible for children to have rects outside our bounds, then we need to descend into
   2231     // the children and compute them.
   2232     // Ideally there would be other cases where we could detect that children couldn't have rects
   2233     // outside our bounds and prune the tree walk.
   2234     // Note that we don't use Region here because Union is O(N) - better to just keep a list of
   2235     // partially redundant rectangles. If we find examples where this is expensive, then we could
   2236     // rewrite Region to be more efficient. See https://bugs.webkit.org/show_bug.cgi?id=100814.
   2237     if (!isRenderView()) {
   2238         for (RenderObject* curr = slowFirstChild(); curr; curr = curr->nextSibling()) {
   2239             curr->addLayerHitTestRects(layerRects, currentLayer,  layerOffset, newContainerRect);
   2240         }
   2241     }
   2242 }
   2243 
   2244 bool RenderObject::isRooted() const
   2245 {
   2246     const RenderObject* object = this;
   2247     while (object->parent() && !object->hasLayer())
   2248         object = object->parent();
   2249     if (object->hasLayer())
   2250         return toRenderLayerModelObject(object)->layer()->root()->isRootLayer();
   2251     return false;
   2252 }
   2253 
   2254 RenderObject* RenderObject::rendererForRootBackground()
   2255 {
   2256     ASSERT(isDocumentElement());
   2257     if (!hasBackground() && isHTMLHtmlElement(node())) {
   2258         // Locate the <body> element using the DOM. This is easier than trying
   2259         // to crawl around a render tree with potential :before/:after content and
   2260         // anonymous blocks created by inline <body> tags etc. We can locate the <body>
   2261         // render object very easily via the DOM.
   2262         HTMLElement* body = document().body();
   2263         RenderObject* bodyObject = isHTMLBodyElement(body) ? body->renderer() : 0;
   2264         if (bodyObject)
   2265             return bodyObject;
   2266     }
   2267 
   2268     return this;
   2269 }
   2270 
   2271 RespectImageOrientationEnum RenderObject::shouldRespectImageOrientation() const
   2272 {
   2273     // Respect the image's orientation if it's being used as a full-page image or it's
   2274     // an <img> and the setting to respect it everywhere is set.
   2275     return document().isImageDocument()
   2276         || (document().settings() && document().settings()->shouldRespectImageOrientation() && isHTMLImageElement(node())) ? RespectImageOrientation : DoNotRespectImageOrientation;
   2277 }
   2278 
   2279 bool RenderObject::hasEntirelyFixedBackground() const
   2280 {
   2281     return m_style->hasEntirelyFixedBackground();
   2282 }
   2283 
   2284 RenderObject* RenderObject::container(const RenderLayerModelObject* paintInvalidationContainer, bool* paintInvalidationContainerSkipped) const
   2285 {
   2286     if (paintInvalidationContainerSkipped)
   2287         *paintInvalidationContainerSkipped = false;
   2288 
   2289     // This method is extremely similar to containingBlock(), but with a few notable
   2290     // exceptions.
   2291     // (1) It can be used on orphaned subtrees, i.e., it can be called safely even when
   2292     // the object is not part of the primary document subtree yet.
   2293     // (2) For normal flow elements, it just returns the parent.
   2294     // (3) For absolute positioned elements, it will return a relative positioned inline.
   2295     // containingBlock() simply skips relpositioned inlines and lets an enclosing block handle
   2296     // the layout of the positioned object.  This does mean that computePositionedLogicalWidth and
   2297     // computePositionedLogicalHeight have to use container().
   2298     RenderObject* o = parent();
   2299 
   2300     if (isText())
   2301         return o;
   2302 
   2303     EPosition pos = m_style->position();
   2304     if (pos == FixedPosition) {
   2305         return containerForFixedPosition(paintInvalidationContainer, paintInvalidationContainerSkipped);
   2306     } else if (pos == AbsolutePosition) {
   2307         // We technically just want our containing block, but
   2308         // we may not have one if we're part of an uninstalled
   2309         // subtree. We'll climb as high as we can though.
   2310         while (o) {
   2311             if (o->style()->position() != StaticPosition)
   2312                 break;
   2313 
   2314             if (o->canContainFixedPositionObjects())
   2315                 break;
   2316 
   2317             if (paintInvalidationContainerSkipped && o == paintInvalidationContainer)
   2318                 *paintInvalidationContainerSkipped = true;
   2319 
   2320             o = o->parent();
   2321         }
   2322     }
   2323 
   2324     return o;
   2325 }
   2326 
   2327 bool RenderObject::isSelectionBorder() const
   2328 {
   2329     SelectionState st = selectionState();
   2330     return st == SelectionStart || st == SelectionEnd || st == SelectionBoth;
   2331 }
   2332 
   2333 inline void RenderObject::clearLayoutRootIfNeeded() const
   2334 {
   2335     if (frame()) {
   2336         if (FrameView* view = frame()->view()) {
   2337             if (view->layoutRoot() == this) {
   2338                 if (!documentBeingDestroyed())
   2339                     ASSERT_NOT_REACHED();
   2340                 // This indicates a failure to layout the child, which is why
   2341                 // the layout root is still set to |this|. Make sure to clear it
   2342                 // since we are getting destroyed.
   2343                 view->clearLayoutSubtreeRoot();
   2344             }
   2345         }
   2346     }
   2347 }
   2348 
   2349 void RenderObject::willBeDestroyed()
   2350 {
   2351     // Destroy any leftover anonymous children.
   2352     RenderObjectChildList* children = virtualChildren();
   2353     if (children)
   2354         children->destroyLeftoverChildren();
   2355 
   2356     // If this renderer is being autoscrolled, stop the autoscrolling.
   2357     if (LocalFrame* frame = this->frame()) {
   2358         if (frame->page())
   2359             frame->page()->autoscrollController().stopAutoscrollIfNeeded(this);
   2360     }
   2361 
   2362     // For accessibility management, notify the parent of the imminent change to its child set.
   2363     // We do it now, before remove(), while the parent pointer is still available.
   2364     if (AXObjectCache* cache = document().existingAXObjectCache())
   2365         cache->childrenChanged(this->parent());
   2366 
   2367     remove();
   2368 
   2369     // The remove() call above may invoke axObjectCache()->childrenChanged() on the parent, which may require the AX render
   2370     // object for this renderer. So we remove the AX render object now, after the renderer is removed.
   2371     if (AXObjectCache* cache = document().existingAXObjectCache())
   2372         cache->remove(this);
   2373 
   2374     // If this renderer had a parent, remove should have destroyed any counters
   2375     // attached to this renderer and marked the affected other counters for
   2376     // reevaluation. This apparently redundant check is here for the case when
   2377     // this renderer had no parent at the time remove() was called.
   2378 
   2379     if (hasCounterNodeMap())
   2380         RenderCounter::destroyCounterNodes(*this);
   2381 
   2382     // Remove the handler if node had touch-action set. Don't call when
   2383     // document is being destroyed as all handlers will have been cleared
   2384     // previously. Handlers are not added for text nodes so don't try removing
   2385     // for one too. Need to check if m_style is null in cases of partial construction.
   2386     if (!documentBeingDestroyed() && node() && !node()->isTextNode() && m_style && m_style->touchAction() != TouchActionAuto)
   2387         document().frameHost()->eventHandlerRegistry().didRemoveEventHandler(*node(), EventHandlerRegistry::TouchEvent);
   2388 
   2389     setAncestorLineBoxDirty(false);
   2390 
   2391     clearLayoutRootIfNeeded();
   2392 }
   2393 
   2394 void RenderObject::insertedIntoTree()
   2395 {
   2396     // FIXME: We should ASSERT(isRooted()) here but generated content makes some out-of-order insertion.
   2397 
   2398     // Keep our layer hierarchy updated. Optimize for the common case where we don't have any children
   2399     // and don't have a layer attached to ourselves.
   2400     RenderLayer* layer = 0;
   2401     if (slowFirstChild() || hasLayer()) {
   2402         layer = parent()->enclosingLayer();
   2403         addLayers(layer);
   2404     }
   2405 
   2406     // If |this| is visible but this object was not, tell the layer it has some visible content
   2407     // that needs to be drawn and layer visibility optimization can't be used
   2408     if (parent()->style()->visibility() != VISIBLE && style()->visibility() == VISIBLE && !hasLayer()) {
   2409         if (!layer)
   2410             layer = parent()->enclosingLayer();
   2411         if (layer)
   2412             layer->dirtyVisibleContentStatus();
   2413     }
   2414 
   2415     if (!isFloating() && parent()->childrenInline())
   2416         parent()->dirtyLinesFromChangedChild(this);
   2417 }
   2418 
   2419 void RenderObject::willBeRemovedFromTree()
   2420 {
   2421     // FIXME: We should ASSERT(isRooted()) but we have some out-of-order removals which would need to be fixed first.
   2422 
   2423     // If we remove a visible child from an invisible parent, we don't know the layer visibility any more.
   2424     RenderLayer* layer = 0;
   2425     if (parent()->style()->visibility() != VISIBLE && style()->visibility() == VISIBLE && !hasLayer()) {
   2426         layer = parent()->enclosingLayer();
   2427         if (layer)
   2428             layer->dirtyVisibleContentStatus();
   2429     }
   2430 
   2431     // Keep our layer hierarchy updated.
   2432     if (slowFirstChild() || hasLayer()) {
   2433         if (!layer)
   2434             layer = parent()->enclosingLayer();
   2435         removeLayers(layer);
   2436     }
   2437 
   2438     if (isOutOfFlowPositioned() && parent()->childrenInline())
   2439         parent()->dirtyLinesFromChangedChild(this);
   2440 
   2441     removeFromRenderFlowThread();
   2442 
   2443     // Update cached boundaries in SVG renderers if a child is removed.
   2444     if (parent()->isSVG())
   2445         parent()->setNeedsBoundariesUpdate();
   2446 }
   2447 
   2448 void RenderObject::removeFromRenderFlowThread()
   2449 {
   2450     if (flowThreadState() == NotInsideFlowThread)
   2451         return;
   2452 
   2453     // Sometimes we remove the element from the flow, but it's not destroyed at that time.
   2454     // It's only until later when we actually destroy it and remove all the children from it.
   2455     // Currently, that happens for firstLetter elements and list markers.
   2456     // Pass in the flow thread so that we don't have to look it up for all the children.
   2457     removeFromRenderFlowThreadRecursive(flowThreadContainingBlock());
   2458 }
   2459 
   2460 void RenderObject::removeFromRenderFlowThreadRecursive(RenderFlowThread* renderFlowThread)
   2461 {
   2462     if (const RenderObjectChildList* children = virtualChildren()) {
   2463         for (RenderObject* child = children->firstChild(); child; child = child->nextSibling())
   2464             child->removeFromRenderFlowThreadRecursive(renderFlowThread);
   2465     }
   2466 
   2467     setFlowThreadState(NotInsideFlowThread);
   2468 }
   2469 
   2470 void RenderObject::destroyAndCleanupAnonymousWrappers()
   2471 {
   2472     // If the tree is destroyed, there is no need for a clean-up phase.
   2473     if (documentBeingDestroyed()) {
   2474         destroy();
   2475         return;
   2476     }
   2477 
   2478     RenderObject* destroyRoot = this;
   2479     for (RenderObject* destroyRootParent = destroyRoot->parent(); destroyRootParent && destroyRootParent->isAnonymous(); destroyRoot = destroyRootParent, destroyRootParent = destroyRootParent->parent()) {
   2480         // Anonymous block continuations are tracked and destroyed elsewhere (see the bottom of RenderBlock::removeChild)
   2481         if (destroyRootParent->isRenderBlock() && toRenderBlock(destroyRootParent)->isAnonymousBlockContinuation())
   2482             break;
   2483         // Render flow threads are tracked by the FlowThreadController, so we can't destroy them here.
   2484         // Column spans are tracked elsewhere.
   2485         if (destroyRootParent->isRenderFlowThread() || destroyRootParent->isAnonymousColumnSpanBlock())
   2486             break;
   2487 
   2488         if (destroyRootParent->slowFirstChild() != destroyRoot || destroyRootParent->slowLastChild() != destroyRoot)
   2489             break; // Need to keep the anonymous parent, since it won't become empty by the removal of this renderer.
   2490     }
   2491 
   2492     destroyRoot->destroy();
   2493 
   2494     // WARNING: |this| is deleted here.
   2495 }
   2496 
   2497 void RenderObject::destroy()
   2498 {
   2499 #if ENABLE(ASSERT) && ENABLE(OILPAN)
   2500     ASSERT(!m_didCallDestroy);
   2501     m_didCallDestroy = true;
   2502 #endif
   2503     willBeDestroyed();
   2504     postDestroy();
   2505 }
   2506 
   2507 void RenderObject::removeShapeImageClient(ShapeValue* shapeValue)
   2508 {
   2509     if (!shapeValue)
   2510         return;
   2511     if (StyleImage* shapeImage = shapeValue->image())
   2512         shapeImage->removeClient(this);
   2513 }
   2514 
   2515 void RenderObject::postDestroy()
   2516 {
   2517     // It seems ugly that this is not in willBeDestroyed().
   2518     if (m_style) {
   2519         for (const FillLayer* bgLayer = &m_style->backgroundLayers(); bgLayer; bgLayer = bgLayer->next()) {
   2520             if (StyleImage* backgroundImage = bgLayer->image())
   2521                 backgroundImage->removeClient(this);
   2522         }
   2523 
   2524         for (const FillLayer* maskLayer = &m_style->maskLayers(); maskLayer; maskLayer = maskLayer->next()) {
   2525             if (StyleImage* maskImage = maskLayer->image())
   2526                 maskImage->removeClient(this);
   2527         }
   2528 
   2529         if (StyleImage* borderImage = m_style->borderImage().image())
   2530             borderImage->removeClient(this);
   2531 
   2532         if (StyleImage* maskBoxImage = m_style->maskBoxImage().image())
   2533             maskBoxImage->removeClient(this);
   2534 
   2535         removeShapeImageClient(m_style->shapeOutside());
   2536     }
   2537     ResourceLoadPriorityOptimizer::resourceLoadPriorityOptimizer()->removeRenderObject(this);
   2538 #if !ENABLE(OILPAN)
   2539     delete this;
   2540 #endif
   2541 }
   2542 
   2543 PositionWithAffinity RenderObject::positionForPoint(const LayoutPoint&)
   2544 {
   2545     return createPositionWithAffinity(caretMinOffset(), DOWNSTREAM);
   2546 }
   2547 
   2548 void RenderObject::updateDragState(bool dragOn)
   2549 {
   2550     bool valueChanged = (dragOn != isDragging());
   2551     setIsDragging(dragOn);
   2552     if (valueChanged && node()) {
   2553         if (node()->isElementNode() && toElement(node())->childrenOrSiblingsAffectedByDrag())
   2554             node()->setNeedsStyleRecalc(SubtreeStyleChange);
   2555         else if (style()->affectedByDrag())
   2556             node()->setNeedsStyleRecalc(LocalStyleChange);
   2557     }
   2558     for (RenderObject* curr = slowFirstChild(); curr; curr = curr->nextSibling())
   2559         curr->updateDragState(dragOn);
   2560 }
   2561 
   2562 CompositingState RenderObject::compositingState() const
   2563 {
   2564     return hasLayer() ? toRenderLayerModelObject(this)->layer()->compositingState() : NotComposited;
   2565 }
   2566 
   2567 CompositingReasons RenderObject::additionalCompositingReasons() const
   2568 {
   2569     return CompositingReasonNone;
   2570 }
   2571 
   2572 bool RenderObject::hitTest(const HitTestRequest& request, HitTestResult& result, const HitTestLocation& locationInContainer, const LayoutPoint& accumulatedOffset, HitTestFilter hitTestFilter)
   2573 {
   2574     bool inside = false;
   2575     if (hitTestFilter != HitTestSelf) {
   2576         // First test the foreground layer (lines and inlines).
   2577         inside = nodeAtPoint(request, result, locationInContainer, accumulatedOffset, HitTestForeground);
   2578 
   2579         // Test floats next.
   2580         if (!inside)
   2581             inside = nodeAtPoint(request, result, locationInContainer, accumulatedOffset, HitTestFloat);
   2582 
   2583         // Finally test to see if the mouse is in the background (within a child block's background).
   2584         if (!inside)
   2585             inside = nodeAtPoint(request, result, locationInContainer, accumulatedOffset, HitTestChildBlockBackgrounds);
   2586     }
   2587 
   2588     // See if the mouse is inside us but not any of our descendants
   2589     if (hitTestFilter != HitTestDescendants && !inside)
   2590         inside = nodeAtPoint(request, result, locationInContainer, accumulatedOffset, HitTestBlockBackground);
   2591 
   2592     return inside;
   2593 }
   2594 
   2595 void RenderObject::updateHitTestResult(HitTestResult& result, const LayoutPoint& point)
   2596 {
   2597     if (result.innerNode())
   2598         return;
   2599 
   2600     Node* node = this->node();
   2601 
   2602     // If we hit the anonymous renderers inside generated content we should
   2603     // actually hit the generated content so walk up to the PseudoElement.
   2604     if (!node && parent() && parent()->isBeforeOrAfterContent()) {
   2605         for (RenderObject* renderer = parent(); renderer && !node; renderer = renderer->parent())
   2606             node = renderer->node();
   2607     }
   2608 
   2609     if (node) {
   2610         result.setInnerNode(node);
   2611         if (!result.innerNonSharedNode())
   2612             result.setInnerNonSharedNode(node);
   2613         result.setLocalPoint(point);
   2614     }
   2615 }
   2616 
   2617 bool RenderObject::nodeAtPoint(const HitTestRequest&, HitTestResult&, const HitTestLocation& /*locationInContainer*/, const LayoutPoint& /*accumulatedOffset*/, HitTestAction)
   2618 {
   2619     return false;
   2620 }
   2621 
   2622 void RenderObject::scheduleRelayout()
   2623 {
   2624     if (isRenderView()) {
   2625         FrameView* view = toRenderView(this)->frameView();
   2626         if (view)
   2627             view->scheduleRelayout();
   2628     } else {
   2629         if (isRooted()) {
   2630             if (RenderView* renderView = view()) {
   2631                 if (FrameView* frameView = renderView->frameView())
   2632                     frameView->scheduleRelayoutOfSubtree(this);
   2633             }
   2634         }
   2635     }
   2636 }
   2637 
   2638 void RenderObject::forceLayout()
   2639 {
   2640     setSelfNeedsLayout(true);
   2641     setShouldDoFullPaintInvalidation(true);
   2642     layout();
   2643 }
   2644 
   2645 // FIXME: Does this do anything different than forceLayout given that we don't walk
   2646 // the containing block chain. If not, we should change all callers to use forceLayout.
   2647 void RenderObject::forceChildLayout()
   2648 {
   2649     setNormalChildNeedsLayout(true);
   2650     layout();
   2651 }
   2652 
   2653 enum StyleCacheState {
   2654     Cached,
   2655     Uncached
   2656 };
   2657 
   2658 static PassRefPtr<RenderStyle> firstLineStyleForCachedUncachedType(StyleCacheState type, const RenderObject* renderer, RenderStyle* style)
   2659 {
   2660     const RenderObject* rendererForFirstLineStyle = renderer;
   2661     if (renderer->isBeforeOrAfterContent())
   2662         rendererForFirstLineStyle = renderer->parent();
   2663 
   2664     if (rendererForFirstLineStyle->isRenderBlockFlow() || rendererForFirstLineStyle->isRenderButton()) {
   2665         if (RenderBlock* firstLineBlock = rendererForFirstLineStyle->firstLineBlock()) {
   2666             if (type == Cached)
   2667                 return firstLineBlock->getCachedPseudoStyle(FIRST_LINE, style);
   2668             return firstLineBlock->getUncachedPseudoStyle(PseudoStyleRequest(FIRST_LINE), style, firstLineBlock == renderer ? style : 0);
   2669         }
   2670     } else if (!rendererForFirstLineStyle->isAnonymous() && rendererForFirstLineStyle->isRenderInline()) {
   2671         RenderStyle* parentStyle = rendererForFirstLineStyle->parent()->firstLineStyle();
   2672         if (parentStyle != rendererForFirstLineStyle->parent()->style()) {
   2673             if (type == Cached) {
   2674                 // A first-line style is in effect. Cache a first-line style for ourselves.
   2675                 rendererForFirstLineStyle->style()->setHasPseudoStyle(FIRST_LINE_INHERITED);
   2676                 return rendererForFirstLineStyle->getCachedPseudoStyle(FIRST_LINE_INHERITED, parentStyle);
   2677             }
   2678             return rendererForFirstLineStyle->getUncachedPseudoStyle(PseudoStyleRequest(FIRST_LINE_INHERITED), parentStyle, style);
   2679         }
   2680     }
   2681     return nullptr;
   2682 }
   2683 
   2684 PassRefPtr<RenderStyle> RenderObject::uncachedFirstLineStyle(RenderStyle* style) const
   2685 {
   2686     if (!document().styleEngine()->usesFirstLineRules())
   2687         return nullptr;
   2688 
   2689     ASSERT(!isText());
   2690 
   2691     return firstLineStyleForCachedUncachedType(Uncached, this, style);
   2692 }
   2693 
   2694 RenderStyle* RenderObject::cachedFirstLineStyle() const
   2695 {
   2696     ASSERT(document().styleEngine()->usesFirstLineRules());
   2697 
   2698     if (RefPtr<RenderStyle> style = firstLineStyleForCachedUncachedType(Cached, isText() ? parent() : this, m_style.get()))
   2699         return style.get();
   2700 
   2701     return m_style.get();
   2702 }
   2703 
   2704 RenderStyle* RenderObject::getCachedPseudoStyle(PseudoId pseudo, RenderStyle* parentStyle) const
   2705 {
   2706     if (pseudo < FIRST_INTERNAL_PSEUDOID && !style()->hasPseudoStyle(pseudo))
   2707         return 0;
   2708 
   2709     RenderStyle* cachedStyle = style()->getCachedPseudoStyle(pseudo);
   2710     if (cachedStyle)
   2711         return cachedStyle;
   2712 
   2713     RefPtr<RenderStyle> result = getUncachedPseudoStyle(PseudoStyleRequest(pseudo), parentStyle);
   2714     if (result)
   2715         return style()->addCachedPseudoStyle(result.release());
   2716     return 0;
   2717 }
   2718 
   2719 PassRefPtr<RenderStyle> RenderObject::getUncachedPseudoStyle(const PseudoStyleRequest& pseudoStyleRequest, RenderStyle* parentStyle, RenderStyle* ownStyle) const
   2720 {
   2721     if (pseudoStyleRequest.pseudoId < FIRST_INTERNAL_PSEUDOID && !ownStyle && !style()->hasPseudoStyle(pseudoStyleRequest.pseudoId))
   2722         return nullptr;
   2723 
   2724     if (!parentStyle) {
   2725         ASSERT(!ownStyle);
   2726         parentStyle = style();
   2727     }
   2728 
   2729     if (!node())
   2730         return nullptr;
   2731 
   2732     Element* element = Traversal<Element>::firstAncestorOrSelf(*node());
   2733     if (!element)
   2734         return nullptr;
   2735 
   2736     if (pseudoStyleRequest.pseudoId == FIRST_LINE_INHERITED) {
   2737         RefPtr<RenderStyle> result = document().ensureStyleResolver().styleForElement(element, parentStyle, DisallowStyleSharing);
   2738         result->setStyleType(FIRST_LINE_INHERITED);
   2739         return result.release();
   2740     }
   2741 
   2742     return document().ensureStyleResolver().pseudoStyleForElement(element, pseudoStyleRequest, parentStyle);
   2743 }
   2744 
   2745 PassRefPtr<RenderStyle> RenderObject::getUncachedPseudoStyleFromParentOrShadowHost() const
   2746 {
   2747     if (!node())
   2748         return nullptr;
   2749 
   2750     if (ShadowRoot* root = node()->containingShadowRoot()) {
   2751         if (root->type() == ShadowRoot::UserAgentShadowRoot) {
   2752             if (Element* shadowHost = node()->shadowHost()) {
   2753                 return shadowHost->renderer()->getUncachedPseudoStyle(PseudoStyleRequest(SELECTION));
   2754             }
   2755         }
   2756     }
   2757 
   2758     return getUncachedPseudoStyle(PseudoStyleRequest(SELECTION));
   2759 }
   2760 
   2761 bool RenderObject::hasBlendMode() const
   2762 {
   2763     return RuntimeEnabledFeatures::cssCompositingEnabled() && style() && style()->hasBlendMode();
   2764 }
   2765 
   2766 void RenderObject::getTextDecorations(unsigned decorations, AppliedTextDecoration& underline, AppliedTextDecoration& overline, AppliedTextDecoration& linethrough, bool quirksMode, bool firstlineStyle)
   2767 {
   2768     RenderObject* curr = this;
   2769     RenderStyle* styleToUse = 0;
   2770     unsigned currDecs = TextDecorationNone;
   2771     Color resultColor;
   2772     TextDecorationStyle resultStyle;
   2773     do {
   2774         styleToUse = curr->style(firstlineStyle);
   2775         currDecs = styleToUse->textDecoration();
   2776         currDecs &= decorations;
   2777         resultColor = styleToUse->visitedDependentDecorationColor();
   2778         resultStyle = styleToUse->textDecorationStyle();
   2779         // Parameter 'decorations' is cast as an int to enable the bitwise operations below.
   2780         if (currDecs) {
   2781             if (currDecs & TextDecorationUnderline) {
   2782                 decorations &= ~TextDecorationUnderline;
   2783                 underline.color = resultColor;
   2784                 underline.style = resultStyle;
   2785             }
   2786             if (currDecs & TextDecorationOverline) {
   2787                 decorations &= ~TextDecorationOverline;
   2788                 overline.color = resultColor;
   2789                 overline.style = resultStyle;
   2790             }
   2791             if (currDecs & TextDecorationLineThrough) {
   2792                 decorations &= ~TextDecorationLineThrough;
   2793                 linethrough.color = resultColor;
   2794                 linethrough.style = resultStyle;
   2795             }
   2796         }
   2797         if (curr->isRubyText())
   2798             return;
   2799         curr = curr->parent();
   2800         if (curr && curr->isAnonymousBlock() && toRenderBlock(curr)->continuation())
   2801             curr = toRenderBlock(curr)->continuation();
   2802     } while (curr && decorations && (!quirksMode || !curr->node() || (!isHTMLAnchorElement(*curr->node()) && !isHTMLFontElement(*curr->node()))));
   2803 
   2804     // If we bailed out, use the element we bailed out at (typically a <font> or <a> element).
   2805     if (decorations && curr) {
   2806         styleToUse = curr->style(firstlineStyle);
   2807         resultColor = styleToUse->visitedDependentDecorationColor();
   2808         if (decorations & TextDecorationUnderline) {
   2809             underline.color = resultColor;
   2810             underline.style = resultStyle;
   2811         }
   2812         if (decorations & TextDecorationOverline) {
   2813             overline.color = resultColor;
   2814             overline.style = resultStyle;
   2815         }
   2816         if (decorations & TextDecorationLineThrough) {
   2817             linethrough.color = resultColor;
   2818             linethrough.style = resultStyle;
   2819         }
   2820     }
   2821 }
   2822 
   2823 void RenderObject::addAnnotatedRegions(Vector<AnnotatedRegionValue>& regions)
   2824 {
   2825     // Convert the style regions to absolute coordinates.
   2826     if (style()->visibility() != VISIBLE || !isBox())
   2827         return;
   2828 
   2829     if (style()->getDraggableRegionMode() == DraggableRegionNone)
   2830         return;
   2831 
   2832     RenderBox* box = toRenderBox(this);
   2833     FloatRect localBounds(FloatPoint(), FloatSize(box->width().toFloat(), box->height().toFloat()));
   2834     FloatRect absBounds = localToAbsoluteQuad(localBounds).boundingBox();
   2835 
   2836     AnnotatedRegionValue region;
   2837     region.draggable = style()->getDraggableRegionMode() == DraggableRegionDrag;
   2838     region.bounds = LayoutRect(absBounds);
   2839     regions.append(region);
   2840 }
   2841 
   2842 void RenderObject::collectAnnotatedRegions(Vector<AnnotatedRegionValue>& regions)
   2843 {
   2844     // RenderTexts don't have their own style, they just use their parent's style,
   2845     // so we don't want to include them.
   2846     if (isText())
   2847         return;
   2848 
   2849     addAnnotatedRegions(regions);
   2850     for (RenderObject* curr = slowFirstChild(); curr; curr = curr->nextSibling())
   2851         curr->collectAnnotatedRegions(regions);
   2852 }
   2853 
   2854 bool RenderObject::willRenderImage(ImageResource*)
   2855 {
   2856     // Without visibility we won't render (and therefore don't care about animation).
   2857     if (style()->visibility() != VISIBLE)
   2858         return false;
   2859 
   2860     // We will not render a new image when Active DOM is suspended
   2861     if (document().activeDOMObjectsAreSuspended())
   2862         return false;
   2863 
   2864     // If we're not in a window (i.e., we're dormant from being in a background tab)
   2865     // then we don't want to render either.
   2866     return document().view()->isVisible();
   2867 }
   2868 
   2869 int RenderObject::caretMinOffset() const
   2870 {
   2871     return 0;
   2872 }
   2873 
   2874 int RenderObject::caretMaxOffset() const
   2875 {
   2876     if (isReplaced())
   2877         return node() ? std::max(1U, node()->countChildren()) : 1;
   2878     if (isHR())
   2879         return 1;
   2880     return 0;
   2881 }
   2882 
   2883 int RenderObject::previousOffset(int current) const
   2884 {
   2885     return current - 1;
   2886 }
   2887 
   2888 int RenderObject::previousOffsetForBackwardDeletion(int current) const
   2889 {
   2890     return current - 1;
   2891 }
   2892 
   2893 int RenderObject::nextOffset(int current) const
   2894 {
   2895     return current + 1;
   2896 }
   2897 
   2898 bool RenderObject::isInert() const
   2899 {
   2900     const RenderObject* renderer = this;
   2901     while (!renderer->node())
   2902         renderer = renderer->parent();
   2903     return renderer->node()->isInert();
   2904 }
   2905 
   2906 // touch-action applies to all elements with both width AND height properties.
   2907 // According to the CSS Box Model Spec (http://dev.w3.org/csswg/css-box/#the-width-and-height-properties)
   2908 // width applies to all elements but non-replaced inline elements, table rows, and row groups and
   2909 // height applies to all elements but non-replaced inline elements, table columns, and column groups.
   2910 bool RenderObject::supportsTouchAction() const
   2911 {
   2912     if (isInline() && !isReplaced())
   2913         return false;
   2914     if (isTableRow() || isRenderTableCol())
   2915         return false;
   2916 
   2917     return true;
   2918 }
   2919 
   2920 void RenderObject::imageChanged(ImageResource* image, const IntRect* rect)
   2921 {
   2922     imageChanged(static_cast<WrappedImagePtr>(image), rect);
   2923 }
   2924 
   2925 Element* RenderObject::offsetParent() const
   2926 {
   2927     if (isDocumentElement() || isBody())
   2928         return 0;
   2929 
   2930     if (isOutOfFlowPositioned() && style()->position() == FixedPosition)
   2931         return 0;
   2932 
   2933     // If A is an area HTML element which has a map HTML element somewhere in the ancestor
   2934     // chain return the nearest ancestor map HTML element and stop this algorithm.
   2935     // FIXME: Implement!
   2936 
   2937     float effectiveZoom = style()->effectiveZoom();
   2938     Node* node = 0;
   2939     for (RenderObject* ancestor = parent(); ancestor; ancestor = ancestor->parent()) {
   2940         // Spec: http://www.w3.org/TR/cssom-view/#offset-attributes
   2941 
   2942         node = ancestor->node();
   2943 
   2944         if (!node)
   2945             continue;
   2946 
   2947         if (ancestor->isPositioned())
   2948             break;
   2949 
   2950         if (isHTMLBodyElement(*node))
   2951             break;
   2952 
   2953         if (!isPositioned() && (isHTMLTableElement(*node) || isHTMLTableCellElement(*node)))
   2954             break;
   2955 
   2956         // Webkit specific extension where offsetParent stops at zoom level changes.
   2957         if (effectiveZoom != ancestor->style()->effectiveZoom())
   2958             break;
   2959     }
   2960 
   2961     return node && node->isElementNode() ? toElement(node) : 0;
   2962 }
   2963 
   2964 PositionWithAffinity RenderObject::createPositionWithAffinity(int offset, EAffinity affinity)
   2965 {
   2966     // If this is a non-anonymous renderer in an editable area, then it's simple.
   2967     if (Node* node = nonPseudoNode()) {
   2968         if (!node->hasEditableStyle()) {
   2969             // If it can be found, we prefer a visually equivalent position that is editable.
   2970             Position position = createLegacyEditingPosition(node, offset);
   2971             Position candidate = position.downstream(CanCrossEditingBoundary);
   2972             if (candidate.deprecatedNode()->hasEditableStyle())
   2973                 return PositionWithAffinity(candidate, affinity);
   2974             candidate = position.upstream(CanCrossEditingBoundary);
   2975             if (candidate.deprecatedNode()->hasEditableStyle())
   2976                 return PositionWithAffinity(candidate, affinity);
   2977         }
   2978         // FIXME: Eliminate legacy editing positions
   2979         return PositionWithAffinity(createLegacyEditingPosition(node, offset), affinity);
   2980     }
   2981 
   2982     // We don't want to cross the boundary between editable and non-editable
   2983     // regions of the document, but that is either impossible or at least
   2984     // extremely unlikely in any normal case because we stop as soon as we
   2985     // find a single non-anonymous renderer.
   2986 
   2987     // Find a nearby non-anonymous renderer.
   2988     RenderObject* child = this;
   2989     while (RenderObject* parent = child->parent()) {
   2990         // Find non-anonymous content after.
   2991         for (RenderObject* renderer = child->nextInPreOrder(parent); renderer; renderer = renderer->nextInPreOrder(parent)) {
   2992             if (Node* node = renderer->nonPseudoNode())
   2993                 return PositionWithAffinity(firstPositionInOrBeforeNode(node), DOWNSTREAM);
   2994         }
   2995 
   2996         // Find non-anonymous content before.
   2997         for (RenderObject* renderer = child->previousInPreOrder(); renderer; renderer = renderer->previousInPreOrder()) {
   2998             if (renderer == parent)
   2999                 break;
   3000             if (Node* node = renderer->nonPseudoNode())
   3001                 return PositionWithAffinity(lastPositionInOrAfterNode(node), DOWNSTREAM);
   3002         }
   3003 
   3004         // Use the parent itself unless it too is anonymous.
   3005         if (Node* node = parent->nonPseudoNode())
   3006             return PositionWithAffinity(firstPositionInOrBeforeNode(node), DOWNSTREAM);
   3007 
   3008         // Repeat at the next level up.
   3009         child = parent;
   3010     }
   3011 
   3012     // Everything was anonymous. Give up.
   3013     return PositionWithAffinity();
   3014 }
   3015 
   3016 PositionWithAffinity RenderObject::createPositionWithAffinity(const Position& position)
   3017 {
   3018     if (position.isNotNull())
   3019         return PositionWithAffinity(position);
   3020 
   3021     ASSERT(!node());
   3022     return createPositionWithAffinity(0, DOWNSTREAM);
   3023 }
   3024 
   3025 CursorDirective RenderObject::getCursor(const LayoutPoint&, Cursor&) const
   3026 {
   3027     return SetCursorBasedOnStyle;
   3028 }
   3029 
   3030 bool RenderObject::canUpdateSelectionOnRootLineBoxes()
   3031 {
   3032     if (needsLayout())
   3033         return false;
   3034 
   3035     RenderBlock* containingBlock = this->containingBlock();
   3036     return containingBlock ? !containingBlock->needsLayout() : false;
   3037 }
   3038 
   3039 // We only create "generated" child renderers like one for first-letter if:
   3040 // - the firstLetterBlock can have children in the DOM and
   3041 // - the block doesn't have any special assumption on its text children.
   3042 // This correctly prevents form controls from having such renderers.
   3043 bool RenderObject::canHaveGeneratedChildren() const
   3044 {
   3045     return canHaveChildren();
   3046 }
   3047 
   3048 void RenderObject::setNeedsBoundariesUpdate()
   3049 {
   3050     if (RenderObject* renderer = parent())
   3051         renderer->setNeedsBoundariesUpdate();
   3052 }
   3053 
   3054 FloatRect RenderObject::objectBoundingBox() const
   3055 {
   3056     ASSERT_NOT_REACHED();
   3057     return FloatRect();
   3058 }
   3059 
   3060 FloatRect RenderObject::strokeBoundingBox() const
   3061 {
   3062     ASSERT_NOT_REACHED();
   3063     return FloatRect();
   3064 }
   3065 
   3066 // Returns the smallest rectangle enclosing all of the painted content
   3067 // respecting clipping, masking, filters, opacity, stroke-width and markers
   3068 FloatRect RenderObject::paintInvalidationRectInLocalCoordinates() const
   3069 {
   3070     ASSERT_NOT_REACHED();
   3071     return FloatRect();
   3072 }
   3073 
   3074 AffineTransform RenderObject::localTransform() const
   3075 {
   3076     static const AffineTransform identity;
   3077     return identity;
   3078 }
   3079 
   3080 const AffineTransform& RenderObject::localToParentTransform() const
   3081 {
   3082     static const AffineTransform identity;
   3083     return identity;
   3084 }
   3085 
   3086 bool RenderObject::nodeAtFloatPoint(const HitTestRequest&, HitTestResult&, const FloatPoint&, HitTestAction)
   3087 {
   3088     ASSERT_NOT_REACHED();
   3089     return false;
   3090 }
   3091 
   3092 bool RenderObject::isRelayoutBoundaryForInspector() const
   3093 {
   3094     return objectIsRelayoutBoundary(this);
   3095 }
   3096 
   3097 void RenderObject::setShouldDoFullPaintInvalidation(bool b, MarkingBehavior markBehavior)
   3098 {
   3099     // RenderText objects don't know how to invalidate paint for themselves, since they don't know how to compute their bounds.
   3100     // Instead the parent fully invalidate when any text needs full paint invalidation.
   3101     if (isText()) {
   3102         parent()->setShouldDoFullPaintInvalidation(b, markBehavior);
   3103         return;
   3104     }
   3105 
   3106     m_bitfields.setShouldDoFullPaintInvalidation(b);
   3107 
   3108     if (markBehavior == MarkContainingBlockChain && b) {
   3109         ASSERT(document().lifecycle().state() != DocumentLifecycle::InPaintInvalidation);
   3110         frame()->page()->animator().scheduleVisualUpdate(); // In case that this is called not during FrameView::updateLayoutAndStyleForPainting().
   3111         markContainingBlockChainForPaintInvalidation();
   3112     }
   3113 }
   3114 
   3115 void RenderObject::clearPaintInvalidationState(const PaintInvalidationState& paintInvalidationState)
   3116 {
   3117     // paintInvalidationStateIsDirty should be kept in sync with the
   3118     // booleans that are cleared below.
   3119     ASSERT(paintInvalidationState.forceCheckForPaintInvalidation() || paintInvalidationStateIsDirty());
   3120     setShouldDoFullPaintInvalidation(false);
   3121     setShouldDoFullPaintInvalidationIfSelfPaintingLayer(false);
   3122     setOnlyNeededPositionedMovementLayout(false);
   3123     setNeededLayoutBecauseOfChildren(false);
   3124     setShouldInvalidateOverflowForPaint(false);
   3125     setLayoutDidGetCalled(false);
   3126     setMayNeedPaintInvalidation(false);
   3127 }
   3128 
   3129 bool RenderObject::isAllowedToModifyRenderTreeStructure(Document& document)
   3130 {
   3131     return DeprecatedDisableModifyRenderTreeStructureAsserts::canModifyRenderTreeStateInAnyState()
   3132         || document.lifecycle().stateAllowsRenderTreeMutations();
   3133 }
   3134 
   3135 DeprecatedDisableModifyRenderTreeStructureAsserts::DeprecatedDisableModifyRenderTreeStructureAsserts()
   3136     : m_disabler(gModifyRenderTreeStructureAnyState, true)
   3137 {
   3138 }
   3139 
   3140 bool DeprecatedDisableModifyRenderTreeStructureAsserts::canModifyRenderTreeStateInAnyState()
   3141 {
   3142     return gModifyRenderTreeStructureAnyState;
   3143 }
   3144 
   3145 // Since we're only painting non-composited layers, we know that they all share the same paintInvalidationContainer.
   3146 void RenderObject::invalidatePaintIncludingNonCompositingDescendants()
   3147 {
   3148     invalidatePaintIncludingNonCompositingDescendantsInternal(containerForPaintInvalidation());
   3149 }
   3150 
   3151 void RenderObject::invalidatePaintIncludingNonCompositingDescendantsInternal(const RenderLayerModelObject* paintInvalidationContainer)
   3152 {
   3153     invalidatePaintUsingContainer(paintInvalidationContainer, previousPaintInvalidationRect(), InvalidationLayer);
   3154 
   3155     for (RenderObject* child = slowFirstChild(); child; child = child->nextSibling()) {
   3156         if (!child->isPaintInvalidationContainer())
   3157             child->invalidatePaintIncludingNonCompositingDescendantsInternal(paintInvalidationContainer);
   3158     }
   3159 }
   3160 
   3161 
   3162 } // namespace blink
   3163 
   3164 #ifndef NDEBUG
   3165 
   3166 void showTree(const blink::RenderObject* object)
   3167 {
   3168     if (object)
   3169         object->showTreeForThis();
   3170 }
   3171 
   3172 void showLineTree(const blink::RenderObject* object)
   3173 {
   3174     if (object)
   3175         object->showLineTreeForThis();
   3176 }
   3177 
   3178 void showRenderTree(const blink::RenderObject* object1)
   3179 {
   3180     showRenderTree(object1, 0);
   3181 }
   3182 
   3183 void showRenderTree(const blink::RenderObject* object1, const blink::RenderObject* object2)
   3184 {
   3185     if (object1) {
   3186         const blink::RenderObject* root = object1;
   3187         while (root->parent())
   3188             root = root->parent();
   3189         root->showRenderTreeAndMark(object1, "*", object2, "-", 0);
   3190     }
   3191 }
   3192 
   3193 #endif
   3194