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      1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #include "chrome/browser/ui/browser_navigator.h"
      6 
      7 #include <algorithm>
      8 
      9 #include "base/command_line.h"
     10 #include "base/prefs/pref_service.h"
     11 #include "base/strings/stringprintf.h"
     12 #include "base/strings/utf_string_conversions.h"
     13 #include "chrome/browser/browser_about_handler.h"
     14 #include "chrome/browser/chrome_notification_types.h"
     15 #include "chrome/browser/extensions/tab_helper.h"
     16 #include "chrome/browser/prefs/incognito_mode_prefs.h"
     17 #include "chrome/browser/prerender/prerender_manager.h"
     18 #include "chrome/browser/prerender/prerender_manager_factory.h"
     19 #include "chrome/browser/prerender/prerender_util.h"
     20 #include "chrome/browser/profiles/profile.h"
     21 #include "chrome/browser/tab_contents/tab_util.h"
     22 #include "chrome/browser/ui/browser.h"
     23 #include "chrome/browser/ui/browser_finder.h"
     24 #include "chrome/browser/ui/browser_instant_controller.h"
     25 #include "chrome/browser/ui/browser_window.h"
     26 #include "chrome/browser/ui/host_desktop.h"
     27 #include "chrome/browser/ui/omnibox/location_bar.h"
     28 #include "chrome/browser/ui/search/instant_search_prerenderer.h"
     29 #include "chrome/browser/ui/singleton_tabs.h"
     30 #include "chrome/browser/ui/status_bubble.h"
     31 #include "chrome/browser/ui/tab_helpers.h"
     32 #include "chrome/browser/ui/tabs/tab_strip_model.h"
     33 #include "chrome/browser/web_applications/web_app.h"
     34 #include "chrome/common/pref_names.h"
     35 #include "chrome/common/url_constants.h"
     36 #include "components/google/core/browser/google_url_tracker.h"
     37 #include "content/public/browser/browser_url_handler.h"
     38 #include "content/public/browser/navigation_entry.h"
     39 #include "content/public/browser/notification_service.h"
     40 #include "content/public/browser/render_view_host.h"
     41 #include "content/public/browser/web_contents.h"
     42 #include "extensions/browser/extension_registry.h"
     43 #include "extensions/common/extension.h"
     44 #include "extensions/common/extension_set.h"
     45 
     46 #if defined(USE_ASH)
     47 #include "chrome/browser/ui/ash/multi_user/multi_user_window_manager.h"
     48 #endif
     49 #if defined(USE_AURA)
     50 #include "ui/aura/window.h"
     51 #endif
     52 
     53 using content::GlobalRequestID;
     54 using content::NavigationController;
     55 using content::WebContents;
     56 
     57 class BrowserNavigatorWebContentsAdoption {
     58  public:
     59   static void AttachTabHelpers(content::WebContents* contents) {
     60     TabHelpers::AttachTabHelpers(contents);
     61   }
     62 };
     63 
     64 namespace {
     65 
     66 // Returns true if the specified Browser can open tabs. Not all Browsers support
     67 // multiple tabs, such as app frames and popups. This function returns false for
     68 // those types of Browser.
     69 bool WindowCanOpenTabs(Browser* browser) {
     70   return browser->CanSupportWindowFeature(Browser::FEATURE_TABSTRIP) ||
     71       browser->tab_strip_model()->empty();
     72 }
     73 
     74 // Finds an existing Browser compatible with |profile|, making a new one if no
     75 // such Browser is located.
     76 Browser* GetOrCreateBrowser(Profile* profile,
     77                             chrome::HostDesktopType host_desktop_type) {
     78   Browser* browser = chrome::FindTabbedBrowser(profile, false,
     79                                                host_desktop_type);
     80   return browser ? browser : new Browser(
     81       Browser::CreateParams(profile, host_desktop_type));
     82 }
     83 
     84 // Change some of the navigation parameters based on the particular URL.
     85 // Currently this applies to some chrome:// pages which we always want to open
     86 // in a non-incognito window. Note that even though a ChromeOS guest session is
     87 // technically an incognito window, these URLs are allowed.
     88 // Returns true on success. Otherwise, if changing params leads the browser into
     89 // an erroneous state, returns false.
     90 bool AdjustNavigateParamsForURL(chrome::NavigateParams* params) {
     91   if (params->target_contents != NULL ||
     92       chrome::IsURLAllowedInIncognito(params->url,
     93                                       params->initiating_profile) ||
     94       params->initiating_profile->IsGuestSession()) {
     95     return true;
     96   }
     97 
     98   Profile* profile = params->initiating_profile;
     99 
    100   if (profile->IsOffTheRecord() || params->disposition == OFF_THE_RECORD) {
    101     profile = profile->GetOriginalProfile();
    102 
    103     // If incognito is forced, we punt.
    104     PrefService* prefs = profile->GetPrefs();
    105     if (prefs && IncognitoModePrefs::GetAvailability(prefs) ==
    106             IncognitoModePrefs::FORCED) {
    107       return false;
    108     }
    109 
    110     params->disposition = SINGLETON_TAB;
    111     params->browser = GetOrCreateBrowser(profile, params->host_desktop_type);
    112     params->window_action = chrome::NavigateParams::SHOW_WINDOW;
    113   }
    114 
    115   return true;
    116 }
    117 
    118 // Returns a Browser that can host the navigation or tab addition specified in
    119 // |params|. This might just return the same Browser specified in |params|, or
    120 // some other if that Browser is deemed incompatible.
    121 Browser* GetBrowserForDisposition(chrome::NavigateParams* params) {
    122   // If no source WebContents was specified, we use the selected one from
    123   // the target browser. This must happen first, before
    124   // GetBrowserForDisposition() has a chance to replace |params->browser| with
    125   // another one.
    126   if (!params->source_contents && params->browser) {
    127     params->source_contents =
    128         params->browser->tab_strip_model()->GetActiveWebContents();
    129   }
    130 
    131   Profile* profile = params->initiating_profile;
    132 
    133   switch (params->disposition) {
    134     case CURRENT_TAB:
    135       if (params->browser)
    136         return params->browser;
    137       // Find a compatible window and re-execute this command in it. Otherwise
    138       // re-run with NEW_WINDOW.
    139       return GetOrCreateBrowser(profile, params->host_desktop_type);
    140     case SINGLETON_TAB:
    141     case NEW_FOREGROUND_TAB:
    142     case NEW_BACKGROUND_TAB:
    143       // See if we can open the tab in the window this navigator is bound to.
    144       if (params->browser && WindowCanOpenTabs(params->browser))
    145         return params->browser;
    146       // Find a compatible window and re-execute this command in it. Otherwise
    147       // re-run with NEW_WINDOW.
    148       return GetOrCreateBrowser(profile, params->host_desktop_type);
    149     case NEW_POPUP: {
    150       // Make a new popup window.
    151       // Coerce app-style if |source| represents an app.
    152       std::string app_name;
    153       if (!params->extension_app_id.empty()) {
    154         app_name = web_app::GenerateApplicationNameFromExtensionId(
    155             params->extension_app_id);
    156       } else if (params->browser && !params->browser->app_name().empty()) {
    157         app_name = params->browser->app_name();
    158       } else if (params->source_contents) {
    159         extensions::TabHelper* extensions_tab_helper =
    160             extensions::TabHelper::FromWebContents(params->source_contents);
    161         if (extensions_tab_helper && extensions_tab_helper->is_app()) {
    162           app_name = web_app::GenerateApplicationNameFromExtensionId(
    163               extensions_tab_helper->extension_app()->id());
    164         }
    165       }
    166       if (app_name.empty()) {
    167         Browser::CreateParams browser_params(
    168             Browser::TYPE_POPUP, profile, params->host_desktop_type);
    169         browser_params.trusted_source = params->trusted_source;
    170         browser_params.initial_bounds = params->window_bounds;
    171         return new Browser(browser_params);
    172       }
    173 
    174       return new Browser(Browser::CreateParams::CreateForApp(
    175           app_name,
    176           params->trusted_source,
    177           params->window_bounds,
    178           profile,
    179           params->host_desktop_type));
    180     }
    181     case NEW_WINDOW: {
    182       // Make a new normal browser window.
    183       return new Browser(Browser::CreateParams(profile,
    184                                                params->host_desktop_type));
    185     }
    186     case OFF_THE_RECORD:
    187       // Make or find an incognito window.
    188       return GetOrCreateBrowser(profile->GetOffTheRecordProfile(),
    189                                 params->host_desktop_type);
    190     // The following types all result in no navigation.
    191     case SUPPRESS_OPEN:
    192     case SAVE_TO_DISK:
    193     case IGNORE_ACTION:
    194       return NULL;
    195     default:
    196       NOTREACHED();
    197   }
    198   return NULL;
    199 }
    200 
    201 // Fix disposition and other parameter values depending on prevailing
    202 // conditions.
    203 void NormalizeDisposition(chrome::NavigateParams* params) {
    204   // Calculate the WindowOpenDisposition if necessary.
    205   if (params->browser->tab_strip_model()->empty() &&
    206       (params->disposition == NEW_BACKGROUND_TAB ||
    207        params->disposition == CURRENT_TAB ||
    208        params->disposition == SINGLETON_TAB)) {
    209     params->disposition = NEW_FOREGROUND_TAB;
    210   }
    211   if (params->browser->profile()->IsOffTheRecord() &&
    212       params->disposition == OFF_THE_RECORD) {
    213     params->disposition = NEW_FOREGROUND_TAB;
    214   }
    215   if (!params->source_contents && params->disposition == CURRENT_TAB)
    216     params->disposition = NEW_FOREGROUND_TAB;
    217 
    218   switch (params->disposition) {
    219     case NEW_BACKGROUND_TAB:
    220       // Disposition trumps add types. ADD_ACTIVE is a default, so we need to
    221       // remove it if disposition implies the tab is going to open in the
    222       // background.
    223       params->tabstrip_add_types &= ~TabStripModel::ADD_ACTIVE;
    224       break;
    225 
    226     case NEW_WINDOW:
    227     case NEW_POPUP:
    228       // Code that wants to open a new window typically expects it to be shown
    229       // automatically.
    230       if (params->window_action == chrome::NavigateParams::NO_ACTION)
    231         params->window_action = chrome::NavigateParams::SHOW_WINDOW;
    232       // Fall-through.
    233     case NEW_FOREGROUND_TAB:
    234     case SINGLETON_TAB:
    235       params->tabstrip_add_types |= TabStripModel::ADD_ACTIVE;
    236       break;
    237 
    238     default:
    239       break;
    240   }
    241 }
    242 
    243 // Obtain the profile used by the code that originated the Navigate() request.
    244 Profile* GetSourceProfile(chrome::NavigateParams* params) {
    245   if (params->source_contents) {
    246     return Profile::FromBrowserContext(
    247         params->source_contents->GetBrowserContext());
    248   }
    249 
    250   return params->initiating_profile;
    251 }
    252 
    253 void LoadURLInContents(WebContents* target_contents,
    254                        const GURL& url,
    255                        chrome::NavigateParams* params) {
    256   NavigationController::LoadURLParams load_url_params(url);
    257   load_url_params.referrer = params->referrer;
    258   load_url_params.frame_tree_node_id = params->frame_tree_node_id;
    259   load_url_params.redirect_chain = params->redirect_chain;
    260   load_url_params.transition_type = params->transition;
    261   load_url_params.extra_headers = params->extra_headers;
    262   load_url_params.should_replace_current_entry =
    263       params->should_replace_current_entry;
    264 
    265   if (params->transferred_global_request_id != GlobalRequestID()) {
    266     load_url_params.is_renderer_initiated = params->is_renderer_initiated;
    267     load_url_params.transferred_global_request_id =
    268         params->transferred_global_request_id;
    269   } else if (params->is_renderer_initiated) {
    270     load_url_params.is_renderer_initiated = true;
    271   }
    272 
    273   // Only allows the browser-initiated navigation to use POST.
    274   if (params->uses_post && !params->is_renderer_initiated) {
    275     load_url_params.load_type =
    276         NavigationController::LOAD_TYPE_BROWSER_INITIATED_HTTP_POST;
    277     load_url_params.browser_initiated_post_data =
    278         params->browser_initiated_post_data;
    279   }
    280   target_contents->GetController().LoadURLWithParams(load_url_params);
    281 }
    282 
    283 // This class makes sure the Browser object held in |params| is made visible
    284 // by the time it goes out of scope, provided |params| wants it to be shown.
    285 class ScopedBrowserShower {
    286  public:
    287   explicit ScopedBrowserShower(chrome::NavigateParams* params)
    288       : params_(params) {
    289   }
    290   ~ScopedBrowserShower() {
    291     if (params_->window_action == chrome::NavigateParams::SHOW_WINDOW_INACTIVE)
    292       params_->browser->window()->ShowInactive();
    293     else if (params_->window_action == chrome::NavigateParams::SHOW_WINDOW)
    294       params_->browser->window()->Show();
    295   }
    296  private:
    297   chrome::NavigateParams* params_;
    298   DISALLOW_COPY_AND_ASSIGN(ScopedBrowserShower);
    299 };
    300 
    301 // This class manages the lifetime of a WebContents created by the
    302 // Navigate() function. When Navigate() creates a WebContents for a URL,
    303 // an instance of this class takes ownership of it via TakeOwnership() until the
    304 // WebContents is added to a tab strip at which time ownership is
    305 // relinquished via ReleaseOwnership(). If this object goes out of scope without
    306 // being added to a tab strip, the created WebContents is deleted to
    307 // avoid a leak and the params->target_contents field is set to NULL.
    308 class ScopedTargetContentsOwner {
    309  public:
    310   explicit ScopedTargetContentsOwner(chrome::NavigateParams* params)
    311       : params_(params) {
    312   }
    313   ~ScopedTargetContentsOwner() {
    314     if (target_contents_owner_.get())
    315       params_->target_contents = NULL;
    316   }
    317 
    318   // Assumes ownership of |params_|' target_contents until ReleaseOwnership
    319   // is called.
    320   void TakeOwnership() {
    321     target_contents_owner_.reset(params_->target_contents);
    322   }
    323 
    324   // Relinquishes ownership of |params_|' target_contents.
    325   WebContents* ReleaseOwnership() {
    326     return target_contents_owner_.release();
    327   }
    328 
    329  private:
    330   chrome::NavigateParams* params_;
    331   scoped_ptr<WebContents> target_contents_owner_;
    332   DISALLOW_COPY_AND_ASSIGN(ScopedTargetContentsOwner);
    333 };
    334 
    335 content::WebContents* CreateTargetContents(const chrome::NavigateParams& params,
    336                                            const GURL& url) {
    337   WebContents::CreateParams create_params(
    338       params.browser->profile(),
    339       tab_util::GetSiteInstanceForNewTab(params.browser->profile(), url));
    340   if (params.source_contents) {
    341     create_params.initial_size =
    342         params.source_contents->GetContainerBounds().size();
    343     if (params.should_set_opener)
    344       create_params.opener = params.source_contents;
    345   }
    346   if (params.disposition == NEW_BACKGROUND_TAB)
    347     create_params.initially_hidden = true;
    348 
    349 #if defined(USE_AURA)
    350   if (params.browser->window() &&
    351       params.browser->window()->GetNativeWindow()) {
    352     create_params.context =
    353         params.browser->window()->GetNativeWindow();
    354   }
    355 #endif
    356 
    357   WebContents* target_contents = WebContents::Create(create_params);
    358 
    359   // New tabs can have WebUI URLs that will make calls back to arbitrary
    360   // tab helpers, so the entire set of tab helpers needs to be set up
    361   // immediately.
    362   BrowserNavigatorWebContentsAdoption::AttachTabHelpers(target_contents);
    363   extensions::TabHelper::FromWebContents(target_contents)->
    364       SetExtensionAppById(params.extension_app_id);
    365   return target_contents;
    366 }
    367 
    368 // If a prerendered page exists for |url|, replace the page at
    369 // |params->target_contents| with it and update to point to the swapped-in
    370 // WebContents.
    371 bool SwapInPrerender(const GURL& url, chrome::NavigateParams* params) {
    372   Profile* profile =
    373       Profile::FromBrowserContext(params->target_contents->GetBrowserContext());
    374   InstantSearchPrerenderer* prerenderer =
    375       InstantSearchPrerenderer::GetForProfile(profile);
    376   if (prerenderer && prerenderer->UsePrerenderedPage(url, params))
    377     return true;
    378 
    379   prerender::PrerenderManager* prerender_manager =
    380       prerender::PrerenderManagerFactory::GetForProfile(profile);
    381   return prerender_manager &&
    382       prerender_manager->MaybeUsePrerenderedPage(url, params);
    383 }
    384 
    385 chrome::HostDesktopType GetHostDesktop(Browser* browser) {
    386   if (browser)
    387     return browser->host_desktop_type();
    388   return chrome::GetActiveDesktop();
    389 }
    390 
    391 }  // namespace
    392 
    393 namespace chrome {
    394 
    395 NavigateParams::NavigateParams(Browser* a_browser,
    396                                const GURL& a_url,
    397                                content::PageTransition a_transition)
    398     : url(a_url),
    399       frame_tree_node_id(-1),
    400       uses_post(false),
    401       target_contents(NULL),
    402       source_contents(NULL),
    403       disposition(CURRENT_TAB),
    404       trusted_source(false),
    405       transition(a_transition),
    406       is_renderer_initiated(false),
    407       tabstrip_index(-1),
    408       tabstrip_add_types(TabStripModel::ADD_ACTIVE),
    409       window_action(NO_ACTION),
    410       user_gesture(true),
    411       path_behavior(RESPECT),
    412       ref_behavior(IGNORE_REF),
    413       browser(a_browser),
    414       initiating_profile(NULL),
    415       host_desktop_type(GetHostDesktop(a_browser)),
    416       should_replace_current_entry(false),
    417       should_set_opener(false) {
    418 }
    419 
    420 NavigateParams::NavigateParams(Browser* a_browser,
    421                                WebContents* a_target_contents)
    422     : frame_tree_node_id(-1),
    423       uses_post(false),
    424       target_contents(a_target_contents),
    425       source_contents(NULL),
    426       disposition(CURRENT_TAB),
    427       trusted_source(false),
    428       transition(content::PAGE_TRANSITION_LINK),
    429       is_renderer_initiated(false),
    430       tabstrip_index(-1),
    431       tabstrip_add_types(TabStripModel::ADD_ACTIVE),
    432       window_action(NO_ACTION),
    433       user_gesture(true),
    434       path_behavior(RESPECT),
    435       ref_behavior(IGNORE_REF),
    436       browser(a_browser),
    437       initiating_profile(NULL),
    438       host_desktop_type(GetHostDesktop(a_browser)),
    439       should_replace_current_entry(false),
    440       should_set_opener(false) {
    441 }
    442 
    443 NavigateParams::NavigateParams(Profile* a_profile,
    444                                const GURL& a_url,
    445                                content::PageTransition a_transition)
    446     : url(a_url),
    447       frame_tree_node_id(-1),
    448       uses_post(false),
    449       target_contents(NULL),
    450       source_contents(NULL),
    451       disposition(NEW_FOREGROUND_TAB),
    452       trusted_source(false),
    453       transition(a_transition),
    454       is_renderer_initiated(false),
    455       tabstrip_index(-1),
    456       tabstrip_add_types(TabStripModel::ADD_ACTIVE),
    457       window_action(SHOW_WINDOW),
    458       user_gesture(true),
    459       path_behavior(RESPECT),
    460       ref_behavior(IGNORE_REF),
    461       browser(NULL),
    462       initiating_profile(a_profile),
    463       host_desktop_type(chrome::GetActiveDesktop()),
    464       should_replace_current_entry(false),
    465       should_set_opener(false) {
    466 }
    467 
    468 NavigateParams::~NavigateParams() {}
    469 
    470 void FillNavigateParamsFromOpenURLParams(chrome::NavigateParams* nav_params,
    471                                          const content::OpenURLParams& params) {
    472   nav_params->referrer = params.referrer;
    473   nav_params->frame_tree_node_id = params.frame_tree_node_id;
    474   nav_params->redirect_chain = params.redirect_chain;
    475   nav_params->extra_headers = params.extra_headers;
    476   nav_params->disposition = params.disposition;
    477   nav_params->trusted_source = false;
    478   nav_params->is_renderer_initiated = params.is_renderer_initiated;
    479   nav_params->transferred_global_request_id =
    480       params.transferred_global_request_id;
    481   nav_params->should_replace_current_entry =
    482       params.should_replace_current_entry;
    483   nav_params->uses_post = params.uses_post;
    484   nav_params->browser_initiated_post_data = params.browser_initiated_post_data;
    485 }
    486 
    487 void Navigate(NavigateParams* params) {
    488   Browser* source_browser = params->browser;
    489   if (source_browser)
    490     params->initiating_profile = source_browser->profile();
    491   DCHECK(params->initiating_profile);
    492 
    493   if (!AdjustNavigateParamsForURL(params))
    494     return;
    495 
    496   const extensions::Extension* extension =
    497     extensions::ExtensionRegistry::Get(params->initiating_profile)->
    498         enabled_extensions().GetExtensionOrAppByURL(params->url);
    499   // Platform apps cannot navigate. Block the request.
    500   if (extension && extension->is_platform_app())
    501     params->url = GURL(chrome::kExtensionInvalidRequestURL);
    502 
    503   // The browser window may want to adjust the disposition.
    504   if (params->disposition == NEW_POPUP &&
    505       source_browser &&
    506       source_browser->window()) {
    507     params->disposition =
    508         source_browser->window()->GetDispositionForPopupBounds(
    509             params->window_bounds);
    510   }
    511 
    512   params->browser = GetBrowserForDisposition(params);
    513   if (!params->browser)
    514     return;
    515 
    516 #if defined(USE_ASH)
    517   if (source_browser && source_browser != params->browser) {
    518     // When the newly created browser was spawned by a browser which visits
    519     // another user's desktop, it should be shown on the same desktop as the
    520     // originating one. (This is part of the desktop separation per profile).
    521     MultiUserWindowManager* manager = MultiUserWindowManager::GetInstance();
    522     // Some unit tests have no manager instantiated.
    523     if (manager) {
    524       aura::Window* src_window = source_browser->window()->GetNativeWindow();
    525       aura::Window* new_window = params->browser->window()->GetNativeWindow();
    526       const std::string& src_user =
    527           manager->GetUserPresentingWindow(src_window);
    528       if (src_user != manager->GetUserPresentingWindow(new_window)) {
    529         // Once the window gets presented, it should be shown on the same
    530         // desktop as the desktop of the creating browser. Note that this
    531         // command will not show the window if it wasn't shown yet by the
    532         // browser creation.
    533         manager->ShowWindowForUser(new_window, src_user);
    534       }
    535     }
    536   }
    537 #endif
    538 
    539   // Navigate() must not return early after this point.
    540 
    541   if (GetSourceProfile(params) != params->browser->profile()) {
    542     // A tab is being opened from a link from a different profile, we must reset
    543     // source information that may cause state to be shared.
    544     params->source_contents = NULL;
    545     params->referrer = content::Referrer();
    546   }
    547 
    548   // Make sure the Browser is shown if params call for it.
    549   ScopedBrowserShower shower(params);
    550 
    551   // Makes sure any WebContents created by this function is destroyed if
    552   // not properly added to a tab strip.
    553   ScopedTargetContentsOwner target_contents_owner(params);
    554 
    555   // Some dispositions need coercion to base types.
    556   NormalizeDisposition(params);
    557 
    558   // If a new window has been created, it needs to be shown.
    559   if (params->window_action == NavigateParams::NO_ACTION &&
    560       source_browser != params->browser &&
    561       params->browser->tab_strip_model()->empty()) {
    562     params->window_action = NavigateParams::SHOW_WINDOW;
    563   }
    564 
    565   // If we create a popup window from a non user-gesture, don't activate it.
    566   if (params->window_action == NavigateParams::SHOW_WINDOW &&
    567       params->disposition == NEW_POPUP &&
    568       params->user_gesture == false) {
    569     params->window_action = NavigateParams::SHOW_WINDOW_INACTIVE;
    570   }
    571 
    572   // Determine if the navigation was user initiated. If it was, we need to
    573   // inform the target WebContents, and we may need to update the UI.
    574   content::PageTransition base_transition =
    575       content::PageTransitionStripQualifier(params->transition);
    576   bool user_initiated =
    577       params->transition & content::PAGE_TRANSITION_FROM_ADDRESS_BAR ||
    578       base_transition == content::PAGE_TRANSITION_TYPED ||
    579       base_transition == content::PAGE_TRANSITION_AUTO_BOOKMARK ||
    580       base_transition == content::PAGE_TRANSITION_GENERATED ||
    581       base_transition == content::PAGE_TRANSITION_AUTO_TOPLEVEL ||
    582       base_transition == content::PAGE_TRANSITION_RELOAD ||
    583       base_transition == content::PAGE_TRANSITION_KEYWORD;
    584 
    585   // Check if this is a singleton tab that already exists
    586   int singleton_index = chrome::GetIndexOfSingletonTab(params);
    587 
    588   // Did we use a prerender?
    589   bool swapped_in_prerender = false;
    590 
    591   // If no target WebContents was specified, we need to construct one if
    592   // we are supposed to target a new tab; unless it's a singleton that already
    593   // exists.
    594   if (!params->target_contents && singleton_index < 0) {
    595     DCHECK(!params->url.is_empty());
    596     if (params->disposition != CURRENT_TAB) {
    597       params->target_contents = CreateTargetContents(*params, params->url);
    598 
    599       // This function takes ownership of |params->target_contents| until it
    600       // is added to a TabStripModel.
    601       target_contents_owner.TakeOwnership();
    602     } else {
    603       // ... otherwise if we're loading in the current tab, the target is the
    604       // same as the source.
    605       DCHECK(params->source_contents);
    606       params->target_contents = params->source_contents;
    607     }
    608 
    609     // Note: at this point, if |params->disposition| is not CURRENT_TAB,
    610     // |params->target_contents| has not been attached to a Browser yet. (That
    611     // happens later in this function.) However, in that case, the
    612     // sessionStorage namespace could not match, so prerender will use the
    613     // asynchronous codepath and still swap.
    614     DCHECK(params->target_contents);
    615     swapped_in_prerender = SwapInPrerender(params->url, params);
    616 
    617     if (user_initiated)
    618       params->target_contents->UserGestureDone();
    619 
    620     if (!swapped_in_prerender) {
    621       // Try to handle non-navigational URLs that popup dialogs and such, these
    622       // should not actually navigate.
    623       if (!HandleNonNavigationAboutURL(params->url)) {
    624         // Perform the actual navigation, tracking whether it came from the
    625         // renderer.
    626 
    627         LoadURLInContents(params->target_contents, params->url, params);
    628         // For prerender bookkeeping purposes, record that this pending navigate
    629         // originated from chrome::Navigate.
    630         content::NavigationEntry* entry =
    631             params->target_contents->GetController().GetPendingEntry();
    632         if (entry)
    633           entry->SetExtraData(prerender::kChromeNavigateExtraDataKey,
    634                               base::string16());
    635       }
    636     }
    637   } else {
    638     // |target_contents| was specified non-NULL, and so we assume it has already
    639     // been navigated appropriately. We need to do nothing more other than
    640     // add it to the appropriate tabstrip.
    641   }
    642 
    643   // If the user navigated from the omnibox, and the selected tab is going to
    644   // lose focus, then make sure the focus for the source tab goes away from the
    645   // omnibox.
    646   if (params->source_contents &&
    647       (params->disposition == NEW_FOREGROUND_TAB ||
    648        params->disposition == NEW_WINDOW) &&
    649       (params->tabstrip_add_types & TabStripModel::ADD_INHERIT_OPENER))
    650     params->source_contents->Focus();
    651 
    652   if (params->source_contents == params->target_contents ||
    653       (swapped_in_prerender && params->disposition == CURRENT_TAB)) {
    654     // The navigation occurred in the source tab.
    655     params->browser->UpdateUIForNavigationInTab(params->target_contents,
    656                                                 params->transition,
    657                                                 user_initiated);
    658   } else if (singleton_index == -1) {
    659     // If some non-default value is set for the index, we should tell the
    660     // TabStripModel to respect it.
    661     if (params->tabstrip_index != -1)
    662       params->tabstrip_add_types |= TabStripModel::ADD_FORCE_INDEX;
    663 
    664     // The navigation should insert a new tab into the target Browser.
    665     params->browser->tab_strip_model()->AddWebContents(
    666         params->target_contents,
    667         params->tabstrip_index,
    668         params->transition,
    669         params->tabstrip_add_types);
    670     // Now that the |params->target_contents| is safely owned by the target
    671     // Browser's TabStripModel, we can release ownership.
    672     target_contents_owner.ReleaseOwnership();
    673   }
    674 
    675   if (singleton_index >= 0) {
    676     WebContents* target =
    677         params->browser->tab_strip_model()->GetWebContentsAt(singleton_index);
    678 
    679     if (target->IsCrashed()) {
    680       target->GetController().Reload(true);
    681     } else if (params->path_behavior == NavigateParams::IGNORE_AND_NAVIGATE &&
    682         target->GetURL() != params->url) {
    683       LoadURLInContents(target, params->url, params);
    684       // For prerender bookkeeping purposes, record that this pending navigate
    685       // originated from chrome::Navigate.
    686       content::NavigationEntry* entry =
    687           target->GetController().GetPendingEntry();
    688       if (entry)
    689         entry->SetExtraData(prerender::kChromeNavigateExtraDataKey,
    690                             base::string16());
    691     }
    692 
    693     // If the singleton tab isn't already selected, select it.
    694     if (params->source_contents != params->target_contents) {
    695       params->browser->tab_strip_model()->ActivateTabAt(singleton_index,
    696                                                         user_initiated);
    697     }
    698   }
    699 
    700   if (params->disposition != CURRENT_TAB) {
    701     content::NotificationService::current()->Notify(
    702         chrome::NOTIFICATION_TAB_ADDED,
    703         content::Source<content::WebContentsDelegate>(params->browser),
    704         content::Details<WebContents>(params->target_contents));
    705   }
    706 }
    707 
    708 bool IsURLAllowedInIncognito(const GURL& url,
    709                              content::BrowserContext* browser_context) {
    710   if (url.scheme() == content::kViewSourceScheme) {
    711     // A view-source URL is allowed in incognito mode only if the URL itself
    712     // is allowed in incognito mode. Remove the "view-source:" from the start
    713     // of the URL and validate the rest.
    714     std::string stripped_spec = url.spec();
    715     DCHECK_GT(stripped_spec.size(), strlen(content::kViewSourceScheme));
    716     stripped_spec.erase(0, strlen(content::kViewSourceScheme) + 1);
    717     GURL stripped_url(stripped_spec);
    718     return stripped_url.is_valid() &&
    719         IsURLAllowedInIncognito(stripped_url, browser_context);
    720   }
    721   // Most URLs are allowed in incognito; the following are exceptions.
    722   // chrome://extensions is on the list because it redirects to
    723   // chrome://settings.
    724   if (url.scheme() == content::kChromeUIScheme &&
    725       (url.host() == chrome::kChromeUISettingsHost ||
    726        url.host() == chrome::kChromeUISettingsFrameHost ||
    727        url.host() == chrome::kChromeUIExtensionsHost ||
    728        url.host() == chrome::kChromeUIBookmarksHost ||
    729 #if !defined(OS_CHROMEOS)
    730        url.host() == chrome::kChromeUIChromeSigninHost ||
    731 #endif
    732        url.host() == chrome::kChromeUIUberHost ||
    733        url.host() == chrome::kChromeUIThumbnailHost ||
    734        url.host() == chrome::kChromeUIThumbnailHost2 ||
    735        url.host() == chrome::kChromeUIThumbnailListHost ||
    736        url.host() == chrome::kChromeUISuggestionsHost ||
    737        url.host() == chrome::kChromeUIDevicesHost)) {
    738     return false;
    739   }
    740 
    741   if (url.scheme() == chrome::kChromeSearchScheme &&
    742       (url.host() == chrome::kChromeUIThumbnailHost ||
    743        url.host() == chrome::kChromeUIThumbnailHost2 ||
    744        url.host() == chrome::kChromeUIThumbnailListHost ||
    745        url.host() == chrome::kChromeUISuggestionsHost)) {
    746     return false;
    747   }
    748 
    749   GURL rewritten_url = url;
    750   bool reverse_on_redirect = false;
    751   content::BrowserURLHandler::GetInstance()->RewriteURLIfNecessary(
    752       &rewritten_url, browser_context, &reverse_on_redirect);
    753 
    754   // Some URLs are mapped to uber subpages. Do not allow them in incognito.
    755   return !(rewritten_url.scheme() == content::kChromeUIScheme &&
    756            rewritten_url.host() == chrome::kChromeUIUberHost);
    757 }
    758 
    759 }  // namespace chrome
    760