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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 "content/public/common/content_switches.h"
      6 
      7 #include "base/command_line.h"
      8 
      9 namespace switches {
     10 
     11 // The number of MSAA samples for canvas2D. Requires MSAA support by GPU to
     12 // have an effect. 0 disables MSAA.
     13 const char kAcceleratedCanvas2dMSAASampleCount[] = "canvas-msaa-sample-count";
     14 
     15 // By default, file:// URIs cannot read other file:// URIs. This is an
     16 // override for developers who need the old behavior for testing.
     17 const char kAllowFileAccessFromFiles[]      = "allow-file-access-from-files";
     18 
     19 // Allows frames with an https origin to use WebSockets with an insecure URL
     20 // (ws://).
     21 const char kAllowInsecureWebSocketFromHttpsOrigin[] =
     22     "allow-insecure-websocket-from-https-origin";
     23 
     24 // Allows loopback interface to be added in network list for peer connection.
     25 const char kAllowLoopbackInPeerConnection[] =
     26     "allow-loopback-in-peer-connection";
     27 
     28 // Enables the sandboxed processes to run without a job object assigned to them.
     29 // This flag is required to allow Chrome to run in RemoteApps or Citrix. This
     30 // flag can reduce the security of the sandboxed processes and allow them to do
     31 // certain API calls like shut down Windows or access the clipboard. Also we
     32 // lose the chance to kill some processes until the outer job that owns them
     33 // finishes.
     34 const char kAllowNoSandboxJob[]             = "allow-no-sandbox-job";
     35 
     36 // Allows debugging of sandboxed processes (see zygote_main_linux.cc).
     37 const char kAllowSandboxDebugging[]         = "allow-sandbox-debugging";
     38 
     39 // The same as kAuditHandles except all handles are enumerated.
     40 const char kAuditAllHandles[]               = "enable-handle-auditing-all";
     41 
     42 // Enumerates and prints a child process' most dangerous handles when it
     43 // is terminated.
     44 const char kAuditHandles[]                  = "enable-handle-auditing";
     45 
     46 // Choose which logging channels in blink platform to activate.  See
     47 // Logging.cpp in blink's Source/platform for a list of available channels.
     48 const char kBlinkPlatformLogChannels[]      = "blink-platform-log-channels";
     49 
     50 // Block cross-site documents (i.e., HTML/XML/JSON) from being loaded in
     51 // subresources when a document is not supposed to read them.  This will later
     52 // allow us to block them from the entire renderer process when site isolation
     53 // is enabled.
     54 const char kBlockCrossSiteDocuments[]     = "block-cross-site-documents";
     55 
     56 // Causes the browser process to throw an assertion on startup.
     57 const char kBrowserAssertTest[]             = "assert-test";
     58 
     59 // Causes the browser process to crash on startup.
     60 const char kBrowserCrashTest[]              = "crash-test";
     61 
     62 // Path to the exe to run for the renderer and plugin subprocesses.
     63 const char kBrowserSubprocessPath[]         = "browser-subprocess-path";
     64 
     65 // Dumps extra logging about plugin loading to the log file.
     66 const char kDebugPluginLoading[] = "debug-plugin-loading";
     67 
     68 // Sets the tile size used by composited layers.
     69 const char kDefaultTileWidth[]              = "default-tile-width";
     70 const char kDefaultTileHeight[]             = "default-tile-height";
     71 
     72 // Disable antialiasing on 2d canvas.
     73 const char kDisable2dCanvasAntialiasing[]   = "disable-canvas-aa";
     74 
     75 // Disables client-visible 3D APIs, in particular WebGL and Pepper 3D.
     76 // This is controlled by policy and is kept separate from the other
     77 // enable/disable switches to avoid accidentally regressing the policy
     78 // support for controlling access to these APIs.
     79 const char kDisable3DAPIs[]                 = "disable-3d-apis";
     80 
     81 // Disable gpu-accelerated 2d canvas.
     82 const char kDisableAccelerated2dCanvas[]    = "disable-accelerated-2d-canvas";
     83 
     84 // Disables accelerated compositing for backgrounds of root layers with
     85 // background-attachment: fixed.
     86 const char kDisableAcceleratedFixedRootBackground[] =
     87     "disable-accelerated-fixed-root-background";
     88 
     89 // Disables accelerated compositing for overflow scroll.
     90 const char kDisableAcceleratedOverflowScroll[] =
     91     "disable-accelerated-overflow-scroll";
     92 
     93 // Disables layer squashing.
     94 const char kDisableLayerSquashing[] =
     95     "disable-layer-squashing";
     96 
     97 // Disables hardware acceleration of video decode, where available.
     98 const char kDisableAcceleratedVideoDecode[] =
     99     "disable-accelerated-video-decode";
    100 
    101 // Disable the ApplicationCache.
    102 const char kDisableApplicationCache[]       = "disable-application-cache";
    103 
    104 // Disable limits on the number of backing stores. Can prevent blinking for
    105 // users with many windows/tabs and lots of memory.
    106 const char kDisableBackingStoreLimit[]      = "disable-backing-store-limit";
    107 
    108 // See comment for kEnableCompositingForFixedPosition.
    109 const char kDisableCompositingForFixedPosition[] =
    110      "disable-fixed-position-compositing";
    111 
    112 // See comment for kEnableCompositingForTransition.
    113 const char kDisableCompositingForTransition[] =
    114      "disable-transition-compositing";
    115 
    116 // Disables HTML5 DB support.
    117 const char kDisableDatabases[]              = "disable-databases";
    118 
    119 // Disables delegated renderer.
    120 const char kDisableDelegatedRenderer[]      = "disable-delegated-renderer";
    121 
    122 // Disables desktop notifications (default enabled on windows).
    123 const char kDisableDesktopNotifications[]   = "disable-desktop-notifications";
    124 
    125 // Disables experimental navigator content utils implementation.
    126 const char kDisableNavigatorContentUtils[]  =
    127       "disable-navigator-content-utils";
    128 
    129 // Handles URL requests by NPAPI plugins through the renderer.
    130 const char kDisableDirectNPAPIRequests[]    = "disable-direct-npapi-requests";
    131 
    132 // Disable the per-domain blocking for 3D APIs after GPU reset.
    133 // This switch is intended only for tests.
    134 extern const char kDisableDomainBlockingFor3DAPIs[] =
    135     "disable-domain-blocking-for-3d-apis";
    136 
    137 // Disable running the SharedWorker inside the renderer process.
    138 const char kDisableEmbeddedSharedWorker[]    = "disable-embedded-shared-worker";
    139 
    140 // Disable experimental WebGL support.
    141 const char kDisableExperimentalWebGL[]      = "disable-webgl";
    142 
    143 // Disable the fast text autosizing implementation.
    144 const char kDisableFastTextAutosizing[]     = "disable-fast-text-autosizing";
    145 
    146 // Disable FileSystem API.
    147 const char kDisableFileSystem[]             = "disable-file-system";
    148 
    149 // Disable 3D inside of flapper.
    150 const char kDisableFlash3d[]                = "disable-flash-3d";
    151 
    152 // Disable Stage3D inside of flapper.
    153 const char kDisableFlashStage3d[]           = "disable-flash-stage3d";
    154 
    155 const char kDisableGestureTapHighlight[]    = "disable-gesture-tap-highlight";
    156 
    157 // Disables GPU hardware acceleration.  If software renderer is not in place,
    158 // then the GPU process won't launch.
    159 const char kDisableGpu[]                    = "disable-gpu";
    160 
    161 // Prevent the compositor from using its GPU implementation.
    162 const char kDisableGpuCompositing[]         = "disable-gpu-compositing";
    163 
    164 // Disable the limit on the number of times the GPU process may be restarted
    165 // This switch is intended only for tests.
    166 extern const char kDisableGpuProcessCrashLimit[] =
    167     "disable-gpu-process-crash-limit";
    168 
    169 // Disable GPU rasterization, i.e. rasterize on the CPU only.
    170 // Overrides the kEnableGpuRasterization and kForceGpuRasterization flags.
    171 const char kDisableGpuRasterization[]       = "disable-gpu-rasterization";
    172 
    173 // When using CPU rasterizing disable low resolution tiling. This uses
    174 // less power, particularly during animations, but more white may be seen
    175 // during fast scrolling especially on slower devices.
    176 const char kDisableLowResTiling[] = "disable-low-res-tiling";
    177 
    178 // Disable the GPU process sandbox.
    179 const char kDisableGpuSandbox[]             = "disable-gpu-sandbox";
    180 
    181 // Disable the thread that crashes the GPU process if it stops responding to
    182 // messages.
    183 const char kDisableGpuWatchdog[]            = "disable-gpu-watchdog";
    184 
    185 // Suppresses hang monitor dialogs in renderer processes.  This may allow slow
    186 // unload handlers on a page to prevent the tab from closing, but the Task
    187 // Manager can be used to terminate the offending process in this case.
    188 const char kDisableHangMonitor[]            = "disable-hang-monitor";
    189 
    190 // Disable the RenderThread's HistogramCustomizer.
    191 const char kDisableHistogramCustomizer[]    = "disable-histogram-customizer";
    192 
    193 // Paint content on the main thread instead of the compositor thread.
    194 // Overrides the kEnableImplSidePainting flag.
    195 const char kDisableImplSidePainting[]       = "disable-impl-side-painting";
    196 
    197 // Prevent Java from running.
    198 const char kDisableJava[]                   = "disable-java";
    199 
    200 // Don't execute JavaScript (browser JS like the new tab page still runs).
    201 const char kDisableJavaScript[]             = "disable-javascript";
    202 
    203 // Don't kill a child process when it sends a bad IPC message.  Apart
    204 // from testing, it is a bad idea from a security perspective to enable
    205 // this switch.
    206 const char kDisableKillAfterBadIPC[]        = "disable-kill-after-bad-ipc";
    207 
    208 // Disables prefixed Encrypted Media API (e.g. webkitGenerateKeyRequest()).
    209 const char kDisablePrefixedEncryptedMedia[] =
    210     "disable-prefixed-encrypted-media";
    211 
    212 // Disables LCD text.
    213 const char kDisableLCDText[]                = "disable-lcd-text";
    214 
    215 // Disables distance field text.
    216 const char kDisableDistanceFieldText[]      = "disable-distance-field-text";
    217 
    218 // Disable LocalStorage.
    219 const char kDisableLocalStorage[]           = "disable-local-storage";
    220 
    221 // Force logging to be disabled.  Logging is enabled by default in debug
    222 // builds.
    223 const char kDisableLogging[]                = "disable-logging";
    224 
    225 // Disables Media Source API (i.e., the MediaSource object).
    226 const char kDisableMediaSource[]            = "disable-media-source";
    227 
    228 // Disable Pepper3D.
    229 const char kDisablePepper3d[]               = "disable-pepper-3d";
    230 
    231 // Disables compositor-accelerated touch-screen pinch gestures.
    232 const char kDisablePinch[]                  = "disable-pinch";
    233 
    234 // Prevent plugins from running.
    235 const char kDisablePlugins[]                = "disable-plugins";
    236 
    237 // Disable discovering third-party plug-ins. Effectively loading only
    238 // ones shipped with the browser plus third-party ones as specified by
    239 // --extra-plugin-dir and --load-plugin switches.
    240 const char kDisablePluginsDiscovery[]       = "disable-plugins-discovery";
    241 
    242 // Disables remote web font support. SVG font should always work whether this
    243 // option is specified or not.
    244 const char kDisableRemoteFonts[]            = "disable-remote-fonts";
    245 
    246 // Turns off the accessibility in the renderer.
    247 const char kDisableRendererAccessibility[]  = "disable-renderer-accessibility";
    248 
    249 // Disables the new layout/paint system which paints after layout is complete.
    250 const char kDisableRepaintAfterLayout[]     = "disable-repaint-after-layout";
    251 
    252 // Disable the seccomp filter sandbox (seccomp-bpf) (Linux only).
    253 const char kDisableSeccompFilterSandbox[]   = "disable-seccomp-filter-sandbox";
    254 
    255 // Disable session storage.
    256 const char kDisableSessionStorage[]         = "disable-session-storage";
    257 
    258 // Disable the setuid sandbox (Linux only).
    259 const char kDisableSetuidSandbox[]          = "disable-setuid-sandbox";
    260 
    261 // Enable shared workers. Functionality not yet complete.
    262 const char kDisableSharedWorkers[]          = "disable-shared-workers";
    263 
    264 // Disables site-specific tailoring to compatibility issues in WebKit.
    265 const char kDisableSiteSpecificQuirks[]     = "disable-site-specific-quirks";
    266 
    267 // Disable smooth scrolling for testing.
    268 const char kDisableSmoothScrolling[]        = "disable-smooth-scrolling";
    269 
    270 // Disables the use of a 3D software rasterizer.
    271 const char kDisableSoftwareRasterizer[]     = "disable-software-rasterizer";
    272 
    273 // Disable False Start in SSL and TLS connections.
    274 const char kDisableSSLFalseStart[]          = "disable-ssl-false-start";
    275 
    276 // Disable multithreaded GPU compositing of web content.
    277 const char kDisableThreadedCompositing[]     = "disable-threaded-compositing";
    278 
    279 // Don't enforce the same-origin policy. (Used by people testing their sites.)
    280 const char kDisableWebSecurity[]            = "disable-web-security";
    281 
    282 // Disables support for XSLT.
    283 const char kDisableXSLT[]                   = "disable-xslt";
    284 
    285 // Disables Blink's XSSAuditor. The XSSAuditor mitigates reflective XSS.
    286 const char kDisableXSSAuditor[]             = "disable-xss-auditor";
    287 
    288 // Disable rasterizer that writes directly to GPU memory associated with tiles.
    289 // Overrides the kEnableZeroCopy flag.
    290 const char kDisableZeroCopy[]               = "disable-zero-copy";
    291 
    292 // Specifies if the |DOMAutomationController| needs to be bound in the
    293 // renderer. This binding happens on per-frame basis and hence can potentially
    294 // be a performance bottleneck. One should only enable it when automating dom
    295 // based tests.
    296 const char kDomAutomationController[]       = "dom-automation";
    297 
    298 // Enable bleeding-edge code to make Chrome draw content faster. The changes
    299 // behind this path are very likely to break lots of content.
    300 // ** DO NOT use this flag unless you know what you are doing. **
    301 const char kEnableBleedingEdgeRenderingFastPaths[] =
    302     "enable-bleeding-edge-rendering-fast-paths";
    303 
    304 // Disable deferred image filters.
    305 const char kDisableDeferredFilters[]         = "disable-deferred-filters";
    306 
    307 // Enables accelerated compositing for backgrounds of root layers with
    308 // background-attachment: fixed.
    309 const char kEnableAcceleratedFixedRootBackground[] =
    310     "enable-accelerated-fixed-root-background";
    311 
    312 // Enables accelerated compositing for overflow scroll. Promotes eligible
    313 // overflow:scroll elements to layers to enable accelerated scrolling for them.
    314 const char kEnableAcceleratedOverflowScroll[] =
    315     "enable-accelerated-overflow-scroll";
    316 
    317 // Enables LCD text.
    318 const char kEnableLCDText[]                 = "enable-lcd-text";
    319 
    320 // Enables using signed distance fields when rendering text.
    321 // Only valid if GPU rasterization is enabled as well.
    322 const char kEnableDistanceFieldText[]       = "enable-distance-field-text";
    323 
    324 // Enables experimental feature that maps multiple RenderLayers to
    325 // one composited layer to avoid pathological layer counts.
    326 const char kEnableLayerSquashing[] =
    327     "enable-layer-squashing";
    328 
    329 // Enable experimental container node culling.
    330 const char kEnableContainerCulling[]        = "enable-container-culling";
    331 
    332 // Use a BeginFrame signal from browser to renderer to schedule rendering.
    333 const char kEnableBeginFrameScheduling[]    = "enable-begin-frame-scheduling";
    334 
    335 // Enable the creation of compositing layers for fixed position
    336 // elements. Three options are needed to support four possible scenarios:
    337 //  1. Default (disabled)
    338 //  2. Enabled always (to allow dogfooding)
    339 //  3. Disabled always (to give safety fallback for users)
    340 //  4. Enabled only if we detect a highDPI display
    341 //
    342 // Option #4 may soon be the default, because the feature is needed soon for
    343 // high DPI, but cannot be used (yet) for low DPI. Options #2 and #3 will
    344 // override Option #4.
    345 const char kEnableCompositingForFixedPosition[] =
    346      "enable-fixed-position-compositing";
    347 
    348 // Enable/Disable the creation of compositing layers for RenderLayers with a
    349 // transition on a property that supports accelerated animation (that is,
    350 // opacity, -webkit-transform, and -webkit-filter), even when no animation is
    351 // running. These options allow for three possible scenarios:
    352 //  1. Default (enabled only if we dectect a highDPI display)
    353 //  2. Enabled always.
    354 //  3. Disabled always.
    355 const char kEnableCompositingForTransition[] =
    356      "enable-transition-compositing";
    357 
    358 // Defer image decoding in WebKit until painting.
    359 const char kEnableDeferredImageDecoding[]   = "enable-deferred-image-decoding";
    360 
    361 // Enables delegated renderer.
    362 const char kEnableDelegatedRenderer[]       = "enable-delegated-renderer";
    363 
    364 // Enables restarting interrupted downloads.
    365 const char kEnableDownloadResumption[]      = "enable-download-resumption";
    366 
    367 // Enables support for Encrypted Media Extensions (e.g. MediaKeys).
    368 const char kEnableEncryptedMedia[] = "enable-encrypted-media";
    369 
    370 // Enable experimental canvas features, e.g. canvas 2D context attributes
    371 const char kEnableExperimentalCanvasFeatures[] =
    372     "enable-experimental-canvas-features";
    373 
    374 // Enables Web Platform features that are in development.
    375 const char kEnableExperimentalWebPlatformFeatures[] =
    376     "enable-experimental-web-platform-features";
    377 
    378 // By default, cookies are not allowed on file://. They are needed for testing,
    379 // for example page cycler and layout tests. See bug 1157243.
    380 const char kEnableFileCookies[]             = "enable-file-cookies";
    381 
    382 // Enable the fast text autosizing implementation.
    383 const char kEnableFastTextAutosizing[]      = "enable-fast-text-autosizing";
    384 
    385 // Enable Gesture Tap Highlight
    386 const char kEnableGestureTapHighlight[]     = "enable-gesture-tap-highlight";
    387 
    388 // Enables TRACE for GL calls in the renderer.
    389 const char kEnableGpuClientTracing[]        = "enable-gpu-client-tracing";
    390 
    391 // Allow heuristics to determine when a layer tile should be drawn with the
    392 // Skia GPU backend. Only valid with GPU accelerated compositing +
    393 // impl-side painting.
    394 const char kEnableGpuRasterization[]        = "enable-gpu-rasterization";
    395 
    396 // When using CPU rasterizing generate low resolution tiling. Low res
    397 // tiles may be displayed during fast scrolls especially on slower devices.
    398 const char kEnableLowResTiling[] = "enable-low-res-tiling";
    399 
    400 // See comment for kEnableCompositingForFixedPosition.
    401 const char kEnableHighDpiCompositingForFixedPosition[] =
    402      "enable-high-dpi-fixed-position-compositing";
    403 
    404 // Paint content on the compositor thread instead of the main thread.
    405 const char kEnableImplSidePainting[]        = "enable-impl-side-painting";
    406 
    407 // Enables support for inband text tracks in media content.
    408 const char kEnableInbandTextTracks[]        = "enable-inband-text-tracks";
    409 
    410 // Force logging to be enabled.  Logging is disabled by default in release
    411 // builds.
    412 const char kEnableLogging[]                 = "enable-logging";
    413 
    414 // Enables the memory benchmarking extension
    415 const char kEnableMemoryBenchmarking[]      = "enable-memory-benchmarking";
    416 
    417 // Enable rasterizer that writes directly to GPU memory.
    418 const char kEnableOneCopy[]                 = "enable-one-copy";
    419 
    420 // Enables use of hardware overlay for fullscreen video playback. Android only.
    421 const char kEnableOverlayFullscreenVideo[]  = "enable-overlay-fullscreen-video";
    422 
    423 // Disables blink subtitle and media control on top of overlay fullscreen video.
    424 const char kDisableOverlayFullscreenVideoSubtitle[] =
    425     "disable-overlay-fullscreen-video-subtitle";
    426 
    427 // Forward overscroll event data from the renderer to the browser.
    428 const char kEnableOverscrollNotifications[] = "enable-overscroll-notifications";
    429 
    430 // Enables compositor-accelerated touch-screen pinch gestures.
    431 const char kEnablePinch[]                   = "enable-pinch";
    432 
    433 // Make the values returned to window.performance.memory more granular and more
    434 // up to date in shared worker. Without this flag, the memory information is
    435 // still available, but it is bucketized and updated less frequently. This flag
    436 // also applys to workers.
    437 const char kEnablePreciseMemoryInfo[] = "enable-precise-memory-info";
    438 
    439 // Enable caching of pre-parsed JS script data.  See http://crbug.com/32407.
    440 const char kEnablePreparsedJsCaching[]      = "enable-preparsed-js-caching";
    441 
    442 // Enables the CSS multicol implementation that uses the regions implementation.
    443 const char kEnableRegionBasedColumns[] =
    444     "enable-region-based-columns";
    445 
    446 // Enables the new layout/paint system which paints after layout is complete.
    447 const char kEnableRepaintAfterLayout[] =
    448     "enable-repaint-after-layout";
    449 
    450 // Enables targeted style recalculation optimizations.
    451 const char kEnableTargetedStyleRecalc[] =
    452     "enable-targeted-style-recalc";
    453 
    454 // Cause the OS X sandbox write to syslog every time an access to a resource
    455 // is denied by the sandbox.
    456 const char kEnableSandboxLogging[]          = "enable-sandbox-logging";
    457 
    458 // Enables seccomp-bpf support for Android. Requires experimental kernel
    459 // support. <http://crbug.com/166704>
    460 const char kEnableSeccompFilterSandbox[] =
    461     "enable-seccomp-filter-sandbox";
    462 
    463 // Enables the Skia benchmarking extension
    464 const char kEnableSkiaBenchmarking[]        = "enable-skia-benchmarking";
    465 
    466 // On platforms that support it, enables smooth scroll animation.
    467 const char kEnableSmoothScrolling[]         = "enable-smooth-scrolling";
    468 
    469 // Enable spatial navigation
    470 const char kEnableSpatialNavigation[]       = "enable-spatial-navigation";
    471 
    472 // Enables the synthesis part of the Web Speech API.
    473 const char kEnableSpeechSynthesis[]         = "enable-speech-synthesis";
    474 
    475 // Enables StatsTable, logging statistics to a global named shared memory table.
    476 const char kEnableStatsTable[]              = "enable-stats-table";
    477 
    478 // Experimentally ensures that each renderer process:
    479 // 1) Only handles rendering for pages from a single site, apart from iframes.
    480 // (Note that a page can reference content from multiple origins due to images,
    481 // JavaScript files, etc.  Cross-site iframes are also loaded in-process.)
    482 // 2) Only has authority to see or use cookies for the page's top-level origin.
    483 // (So if a.com iframes b.com, the b.com network request will be sent without
    484 // cookies.)
    485 // This is expected to break compatibility with many pages for now.  Unlike the
    486 // --site-per-process flag, this allows cross-site iframes, but it blocks all
    487 // cookies on cross-site requests.
    488 const char kEnableStrictSiteIsolation[]     = "enable-strict-site-isolation";
    489 
    490 // Enable support for ServiceWorker. See
    491 // https://github.com/slightlyoff/ServiceWorker for more information.
    492 const char kEnableServiceWorker[]           = "enable-service-worker";
    493 
    494 // Enable support for sync events in ServiceWorkers.
    495 const char kEnableServiceWorkerSync[]       = "enable-service-worker-sync";
    496 
    497 // Enable use of experimental TCP sockets API for sending data in the
    498 // SYN packet.
    499 const char kEnableTcpFastOpen[]             = "enable-tcp-fastopen";
    500 
    501 // Enable multithreaded GPU compositing of web content.
    502 const char kEnableThreadedCompositing[]     = "enable-threaded-compositing";
    503 
    504 // Enable screen capturing support for MediaStream API.
    505 const char kEnableUserMediaScreenCapturing[] =
    506     "enable-usermedia-screen-capturing";
    507 
    508 // Enables the use of the @viewport CSS rule, which allows
    509 // pages to control aspects of their own layout. This also turns on touch-screen
    510 // pinch gestures.
    511 const char kEnableViewport[]                = "enable-viewport";
    512 
    513 // Enables the use of the legacy viewport meta tag. Turning this on also
    514 // turns on the @viewport CSS rule
    515 const char kEnableViewportMeta[]            = "enable-viewport-meta";
    516 
    517 // Resizes of the main frame are the caused by changing between landscape
    518 // and portrait mode (i.e. Android) so the page should be rescaled to fit
    519 const char kMainFrameResizesAreOrientationChanges[] =
    520     "main-frame-resizes-are-orientation-changes";
    521 
    522 // Enable the Vtune profiler support.
    523 const char kEnableVtune[]                   = "enable-vtune-support";
    524 
    525 // Enable SVG Animations on the Web Animations model.
    526 const char kEnableWebAnimationsSVG[]        = "enable-web-animations-svg";
    527 
    528 // Enables WebGL extensions not yet approved by the community.
    529 const char kEnableWebGLDraftExtensions[] = "enable-webgl-draft-extensions";
    530 
    531 // Enables WebGL rendering into a scanout buffer for overlay support.
    532 const char kEnableWebGLImageChromium[] = "enable-webgl-image-chromium";
    533 
    534 // Enables Web MIDI API.
    535 const char kEnableWebMIDI[]                 = "enable-web-midi";
    536 
    537 // Enable rasterizer that writes directly to GPU memory associated with tiles.
    538 const char kEnableZeroCopy[]                = "enable-zero-copy";
    539 
    540 // Load NPAPI plugins from the specified directory.
    541 const char kExtraPluginDir[]                = "extra-plugin-dir";
    542 
    543 // Some field trials may be randomized in the browser, and the randomly selected
    544 // outcome needs to be propagated to the renderer. For instance, this is used
    545 // to modify histograms recorded in the renderer, or to get the renderer to
    546 // also set of its state (initialize, or not initialize components) to match the
    547 // experiment(s). The option is also useful for forcing field trials when
    548 // testing changes locally. The argument is a list of name and value pairs,
    549 // separated by slashes. See FieldTrialList::CreateTrialsFromString() in
    550 // field_trial.h for details.
    551 const char kForceFieldTrials[]              = "force-fieldtrials";
    552 
    553 // Always use the Skia GPU backend for drawing layer tiles. Only valid with GPU
    554 // accelerated compositing + impl-side painting. Overrides the
    555 // kEnableGpuRasterization flag.
    556 const char kForceGpuRasterization[]        = "force-gpu-rasterization";
    557 
    558 // Force renderer accessibility to be on instead of enabling it on demand when
    559 // a screen reader is detected. The disable-renderer-accessibility switch
    560 // overrides this if present.
    561 const char kForceRendererAccessibility[]    = "force-renderer-accessibility";
    562 
    563 // Passes gpu device_id from browser process to GPU process.
    564 const char kGpuDeviceID[]                   = "gpu-device-id";
    565 
    566 // Passes gpu driver_vendor from browser process to GPU process.
    567 const char kGpuDriverVendor[]               = "gpu-driver-vendor";
    568 
    569 // Passes gpu driver_version from browser process to GPU process.
    570 const char kGpuDriverVersion[]              = "gpu-driver-version";
    571 
    572 // Extra command line options for launching the GPU process (normally used
    573 // for debugging). Use like renderer-cmd-prefix.
    574 const char kGpuLauncher[]                   = "gpu-launcher";
    575 
    576 // Makes this process a GPU sub-process.
    577 const char kGpuProcess[]                    = "gpu-process";
    578 
    579 // Allow shmat system call in GPU sandbox.
    580 const char kGpuSandboxAllowSysVShm[]        = "gpu-sandbox-allow-sysv-shm";
    581 
    582 // Makes GPU sandbox failures fatal.
    583 const char kGpuSandboxFailuresFatal[]       = "gpu-sandbox-failures-fatal";
    584 
    585 // Allow GPU sandbox to start later
    586 const char kGpuSandboxStartAfterInitialization[] =
    587     "gpu-sandbox-start-after-initialization";
    588 
    589 // Causes the GPU process to display a dialog on launch.
    590 const char kGpuStartupDialog[]              = "gpu-startup-dialog";
    591 
    592 // Passes gpu vendor_id from browser process to GPU process.
    593 const char kGpuVendorID[]                   = "gpu-vendor-id";
    594 
    595 // These mappings only apply to the host resolver.
    596 const char kHostResolverRules[]             = "host-resolver-rules";
    597 
    598 // Ignores certificate-related errors.
    599 const char kIgnoreCertificateErrors[]       = "ignore-certificate-errors";
    600 
    601 // Ignores GPU blacklist.
    602 const char kIgnoreGpuBlacklist[]            = "ignore-gpu-blacklist";
    603 
    604 // Run the GPU process as a thread in the browser process.
    605 const char kInProcessGPU[]                  = "in-process-gpu";
    606 
    607 // Overrides the timeout, in seconds, that a child process waits for a
    608 // connection from the browser before killing itself.
    609 const char kIPCConnectionTimeout[]          = "ipc-connection-timeout";
    610 
    611 // Specifies the flags passed to JS engine
    612 const char kJavaScriptFlags[]               = "js-flags";
    613 
    614 // Load an NPAPI plugin from the specified path.
    615 const char kLoadPlugin[]                    = "load-plugin";
    616 
    617 // Logs GPU control list decisions when enforcing blacklist rules.
    618 const char kLogGpuControlListDecisions[]    = "log-gpu-control-list-decisions";
    619 
    620 // Sets the minimum log level. Valid values are from 0 to 3:
    621 // INFO = 0, WARNING = 1, LOG_ERROR = 2, LOG_FATAL = 3.
    622 const char kLoggingLevel[]                  = "log-level";
    623 
    624 // Enables saving net log events to a file and sets the file name to use.
    625 const char kLogNetLog[]                     = "log-net-log";
    626 
    627 // Make plugin processes log their sent and received messages to VLOG(1).
    628 const char kLogPluginMessages[]             = "log-plugin-messages";
    629 
    630 // Sets the width and height above which a composited layer will get tiled.
    631 const char kMaxUntiledLayerHeight[]         = "max-untiled-layer-height";
    632 const char kMaxUntiledLayerWidth[]          = "max-untiled-layer-width";
    633 
    634 // Sample memory usage with high frequency and store the results to the
    635 // Renderer.Memory histogram. Used in memory tests.
    636 const char kMemoryMetrics[]                 = "memory-metrics";
    637 
    638 // Mutes audio sent to the audio device so it is not audible during
    639 // automated testing.
    640 const char kMuteAudio[]                     = "mute-audio";
    641 
    642 // Don't send HTTP-Referer headers.
    643 const char kNoReferrers[]                   = "no-referrers";
    644 
    645 // Disables the sandbox for all process types that are normally sandboxed.
    646 const char kNoSandbox[]                     = "no-sandbox";
    647 
    648 // Number of worker threads used to rasterize content.
    649 const char kNumRasterThreads[]              = "num-raster-threads";
    650 
    651 // Enables or disables history navigation in response to horizontal overscroll.
    652 // Set the value to '1' to enable the feature, and set to '0' to disable.
    653 // Defaults to enabled.
    654 const char kOverscrollHistoryNavigation[] =
    655     "overscroll-history-navigation";
    656 
    657 // Specifies a command that should be used to launch the plugin process.  Useful
    658 // for running the plugin process through purify or quantify.  Ex:
    659 //   --plugin-launcher="path\to\purify /Run=yes"
    660 const char kPluginLauncher[]                = "plugin-launcher";
    661 
    662 // Tells the plugin process the path of the plugin to load
    663 const char kPluginPath[]                    = "plugin-path";
    664 
    665 // Causes the process to run as a plugin subprocess.
    666 const char kPluginProcess[]                 = "plugin";
    667 
    668 // Causes the plugin process to display a dialog on launch.
    669 const char kPluginStartupDialog[]           = "plugin-startup-dialog";
    670 
    671 // Argument to the process type that indicates a PPAPI broker process type.
    672 const char kPpapiBrokerProcess[]            = "ppapi-broker";
    673 
    674 // "Command-line" arguments for the PPAPI Flash; used for debugging options.
    675 const char kPpapiFlashArgs[]                = "ppapi-flash-args";
    676 
    677 // Runs PPAPI (Pepper) plugins in-process.
    678 const char kPpapiInProcess[]                = "ppapi-in-process";
    679 
    680 // Like kPluginLauncher for PPAPI plugins.
    681 const char kPpapiPluginLauncher[]           = "ppapi-plugin-launcher";
    682 
    683 // Argument to the process type that indicates a PPAPI plugin process type.
    684 const char kPpapiPluginProcess[]            = "ppapi";
    685 
    686 // Causes the PPAPI sub process to display a dialog on launch. Be sure to use
    687 // --no-sandbox as well or the sandbox won't allow the dialog to display.
    688 const char kPpapiStartupDialog[]            = "ppapi-startup-dialog";
    689 
    690 // Runs a single process for each site (i.e., group of pages from the same
    691 // registered domain) the user visits.  We default to using a renderer process
    692 // for each site instance (i.e., group of pages from the same registered
    693 // domain with script connections to each other).
    694 const char kProcessPerSite[]                = "process-per-site";
    695 
    696 // Runs each set of script-connected tabs (i.e., a BrowsingInstance) in its own
    697 // renderer process.  We default to using a renderer process for each
    698 // site instance (i.e., group of pages from the same registered domain with
    699 // script connections to each other).
    700 const char kProcessPerTab[]                 = "process-per-tab";
    701 
    702 // The value of this switch determines whether the process is started as a
    703 // renderer or plugin host.  If it's empty, it's the browser.
    704 const char kProcessType[]                   = "type";
    705 
    706 // Enables more web features over insecure connections. Designed to be used
    707 // for testing purposes only.
    708 const char kReduceSecurityForTesting[]      = "reduce-security-for-testing";
    709 
    710 // Register Pepper plugins (see pepper_plugin_list.cc for its format).
    711 const char kRegisterPepperPlugins[]         = "register-pepper-plugins";
    712 
    713 // Enables remote debug over HTTP on the specified port.
    714 const char kRemoteDebuggingPort[]           = "remote-debugging-port";
    715 
    716 // Causes the renderer process to throw an assertion on launch.
    717 const char kRendererAssertTest[]            = "renderer-assert-test";
    718 
    719 // On POSIX only: the contents of this flag are prepended to the renderer
    720 // command line. Useful values might be "valgrind" or "xterm -e gdb --args".
    721 const char kRendererCmdPrefix[]             = "renderer-cmd-prefix";
    722 
    723 // Causes the process to run as renderer instead of as browser.
    724 const char kRendererProcess[]               = "renderer";
    725 
    726 // Overrides the default/calculated limit to the number of renderer processes.
    727 // Very high values for this setting can lead to high memory/resource usage
    728 // or instability.
    729 const char kRendererProcessLimit[]          = "renderer-process-limit";
    730 
    731 // Causes the renderer process to display a dialog on launch.
    732 const char kRendererStartupDialog[]         = "renderer-startup-dialog";
    733 
    734 // Causes the process to run as a sandbox IPC subprocess.
    735 const char kSandboxIPCProcess[]             = "sandbox-ipc";
    736 
    737 // Enables or disables scroll end effect in response to vertical overscroll.
    738 // Set the value to '1' to enable the feature, and set to '0' to disable.
    739 // Defaults to disabled.
    740 const char kScrollEndEffect[] = "scroll-end-effect";
    741 
    742 // Visibly render a border around paint rects in the web page to help debug
    743 // and study painting behavior.
    744 const char kShowPaintRects[]                = "show-paint-rects";
    745 
    746 // Runs the renderer and plugins in the same process as the browser
    747 const char kSingleProcess[]                 = "single-process";
    748 
    749 // Experimentally enforces a one-site-per-process security policy.
    750 // All cross-site navigations force process swaps, and we can restrict a
    751 // renderer process's access rights based on its site.  For details, see:
    752 // http://www.chromium.org/developers/design-documents/site-isolation
    753 //
    754 // Unlike --enable-strict-site-isolation (which allows cross-site iframes),
    755 // this flag does not affect which cookies are attached to cross-site requests.
    756 // Support is being added to render cross-site iframes in a different process
    757 // than their parent pages.
    758 const char kSitePerProcess[]                = "site-per-process";
    759 
    760 // Skip gpu info collection, blacklist loading, and blacklist auto-update
    761 // scheduling at browser startup time.
    762 // Therefore, all GPU features are available, and about:gpu page shows empty
    763 // content. The switch is intended only for layout tests.
    764 // TODO(gab): Get rid of this switch entirely.
    765 const char kSkipGpuDataLoading[]            = "skip-gpu-data-loading";
    766 
    767 // Specifies if the browser should start in fullscreen mode, like if the user
    768 // had pressed F11 right after startup.
    769 const char kStartFullscreen[] = "start-fullscreen";
    770 
    771 // Specifies if the |StatsCollectionController| needs to be bound in the
    772 // renderer. This binding happens on per-frame basis and hence can potentially
    773 // be a performance bottleneck. One should only enable it when running a test
    774 // that needs to access the provided statistics.
    775 const char kStatsCollectionController[] =
    776     "enable-stats-collection-bindings";
    777 
    778 // Upscale defaults to "good".
    779 const char kTabCaptureDownscaleQuality[]    = "tab-capture-downscale-quality";
    780 
    781 // Scaling quality for capturing tab. Should be one of "fast", "good" or "best".
    782 // One flag for upscaling, one for downscaling.
    783 // Upscale defaults to "best".
    784 const char kTabCaptureUpscaleQuality[]      = "tab-capture-upscale-quality";
    785 
    786 // Allows for forcing socket connections to http/https to use fixed ports.
    787 const char kTestingFixedHttpPort[]          = "testing-fixed-http-port";
    788 const char kTestingFixedHttpsPort[]         = "testing-fixed-https-port";
    789 
    790 // Type of the current test harness ("browser" or "ui").
    791 const char kTestType[]                      = "test-type";
    792 
    793 const char kTouchScrollingMode[]            = "touch-scrolling-mode";
    794 const char kTouchScrollingModeAsyncTouchmove[] = "async-touchmove";
    795 const char kTouchScrollingModeSyncTouchmove[] = "sync-touchmove";
    796 const char kTouchScrollingModeTouchcancel[] = "touchcancel";
    797 
    798 // Causes TRACE_EVENT flags to be recorded beginning with shutdown. Optionally,
    799 // can specify the specific trace categories to include (e.g.
    800 // --trace-shutdown=base,net) otherwise, all events are recorded.
    801 // --trace-shutdown-file can be used to control where the trace log gets stored
    802 // to since there is otherwise no way to access the result.
    803 const char kTraceShutdown[]                 = "trace-shutdown";
    804 
    805 // If supplied, sets the file which shutdown tracing will be stored into, if
    806 // omitted the default will be used "chrometrace.log" in the current directory.
    807 // Has no effect unless --trace-shutdown is also supplied.
    808 // Example: --trace-shutdown --trace-shutdown-file=/tmp/trace_event.log
    809 const char kTraceShutdownFile[]             = "trace-shutdown-file";
    810 
    811 // Causes TRACE_EVENT flags to be recorded from startup. Optionally, can
    812 // specify the specific trace categories to include (e.g.
    813 // --trace-startup=base,net) otherwise, all events are recorded. Setting this
    814 // flag results in the first call to BeginTracing() to receive all trace events
    815 // since startup. In Chrome, you may find --trace-startup-file and
    816 // --trace-startup-duration to control the auto-saving of the trace (not
    817 // supported in the base-only TraceLog component).
    818 const char kTraceStartup[]                  = "trace-startup";
    819 
    820 // Sets the time in seconds until startup tracing ends. If omitted a default of
    821 // 5 seconds is used. Has no effect without --trace-startup, or if
    822 // --startup-trace-file=none was supplied.
    823 const char kTraceStartupDuration[]          = "trace-startup-duration";
    824 
    825 // If supplied, sets the file which startup tracing will be stored into, if
    826 // omitted the default will be used "chrometrace.log" in the current directory.
    827 // Has no effect unless --trace-startup is also supplied.
    828 // Example: --trace-startup --trace-startup-file=/tmp/trace_event.log
    829 // As a special case, can be set to 'none' - this disables automatically saving
    830 // the result to a file and the first manually recorded trace will then receive
    831 // all events since startup.
    832 const char kTraceStartupFile[]              = "trace-startup-file";
    833 
    834 
    835 
    836 // Prioritizes the UI's command stream in the GPU process
    837 extern const char kUIPrioritizeInGpuProcess[] =
    838     "ui-prioritize-in-gpu-process";
    839 
    840 // Overrides the preferred discardable memory implementation.
    841 const char kUseDiscardableMemory[] = "use-discardable-memory";
    842 
    843 // Bypass the media stream infobar by selecting the default device for media
    844 // streams (e.g. WebRTC). Works with --use-fake-device-for-media-stream.
    845 const char kUseFakeUIForMediaStream[]     = "use-fake-ui-for-media-stream";
    846 
    847 // Set when Chromium should use a mobile user agent.
    848 const char kUseMobileUserAgent[] = "use-mobile-user-agent";
    849 
    850 // Use the new surfaces system to handle compositor delegation.
    851 const char kUseSurfaces[] = "use-surfaces";
    852 
    853 // On POSIX only: the contents of this flag are prepended to the utility
    854 // process command line. Useful values might be "valgrind" or "xterm -e gdb
    855 // --args".
    856 const char kUtilityCmdPrefix[]              = "utility-cmd-prefix";
    857 
    858 // Causes the process to run as a utility subprocess.
    859 const char kUtilityProcess[]                = "utility";
    860 
    861 // The utility process is sandboxed, with access to one directory. This flag
    862 // specifies the directory that can be accessed.
    863 const char kUtilityProcessAllowedDir[]      = "utility-allowed-dir";
    864 
    865 // Allows MDns to access network in sandboxed process.
    866 const char kUtilityProcessEnableMDns[]      = "utility-enable-mdns";
    867 
    868 const char kUtilityProcessRunningElevated[] = "utility-run-elevated";
    869 
    870 // In debug builds, asserts that the stream of input events is valid.
    871 const char kValidateInputEventStream[] = "validate-input-event-stream";
    872 
    873 // Will add kWaitForDebugger to every child processes. If a value is passed, it
    874 // will be used as a filter to determine if the child process should have the
    875 // kWaitForDebugger flag passed on or not.
    876 const char kWaitForDebuggerChildren[]       = "wait-for-debugger-children";
    877 
    878 // Causes the process to run as a worker subprocess.
    879 const char kWorkerProcess[]                 = "worker";
    880 
    881 // The prefix used when starting the zygote process. (i.e. 'gdb --args')
    882 const char kZygoteCmdPrefix[]               = "zygote-cmd-prefix";
    883 
    884 // Causes the process to run as a renderer zygote.
    885 const char kZygoteProcess[]                 = "zygote";
    886 
    887 #if defined(ENABLE_WEBRTC)
    888 // Disables audio processing in a MediaStreamTrack. When this flag is on, AEC,
    889 // NS and AGC will be done in PeerConnection instead of MediaStreamTrack.
    890 const char kDisableAudioTrackProcessing[]    = "disable-audio-track-processing";
    891 
    892 // Disables WebRTC device enumeration.
    893 const char kDisableDeviceEnumeration[]      = "disable-device-enumeration";
    894 
    895 // Disables HW decode acceleration for WebRTC.
    896 const char kDisableWebRtcHWDecoding[]       = "disable-webrtc-hw-decoding";
    897 
    898 // Disables encryption of RTP Media for WebRTC. When Chrome embeds Content, it
    899 // ignores this switch on its stable and beta channels.
    900 const char kDisableWebRtcEncryption[]      = "disable-webrtc-encryption";
    901 
    902 // Disables HW encode acceleration for WebRTC.
    903 const char kDisableWebRtcHWEncoding[]       = "disable-webrtc-hw-encoding";
    904 
    905 // Enables VP8 HW encode acceleration for WebRTC.
    906 const char kEnableWebRtcHWVp8Encoding[]     = "enable-webrtc-hw-vp8-encoding";
    907 #endif
    908 
    909 #if defined(OS_ANDROID)
    910 // Disable user gesture requirement for media playback.
    911 const char kDisableGestureRequirementForMediaPlayback[] =
    912     "disable-gesture-requirement-for-media-playback";
    913 
    914 // Disable the click delay by sending click events during double tap.
    915 const char kDisableClickDelay[]             = "disable-click-delay";
    916 
    917 // Disable overscroll edge effects like those found in Android views.
    918 const char kDisableOverscrollEdgeEffect[]   = "disable-overscroll-edge-effect";
    919 
    920 // WebRTC is enabled by default on Android.
    921 const char kDisableWebRTC[]                 = "disable-webrtc";
    922 
    923 // Enable the PowerSaveBlocker in ContentVideoView. Android only.
    924 const char kEnableContentVideoViewPowerSaveBlocker[] =
    925     "enable-content-video-view-power-save-blocker";
    926 
    927 // Enable the recognition part of the Web Speech API.
    928 const char kEnableSpeechRecognition[]       = "enable-speech-recognition";
    929 
    930 // Always use the video overlay for the embedded video.
    931 // This switch is intended only for tests.
    932 const char kForceUseOverlayEmbeddedVideo[] = "force-use-overlay-embedded-video";
    933 
    934 // The telephony region (ISO country code) to use in phone number detection.
    935 const char kNetworkCountryIso[] = "network-country-iso";
    936 
    937 // Enables remote debug over HTTP on the specified socket name.
    938 const char kRemoteDebuggingSocketName[]     = "remote-debugging-socket-name";
    939 #endif
    940 
    941 // Disable web audio API.
    942 const char kDisableWebAudio[]               = "disable-webaudio";
    943 
    944 #if defined(OS_CHROMEOS)
    945 // Disables panel fitting (used for mirror mode).
    946 const char kDisablePanelFitting[]           = "disable-panel-fitting";
    947 #endif
    948 
    949 #if defined(OS_MACOSX) && !defined(OS_IOS)
    950 const char kEnableCarbonInterposing[]       = "enable-carbon-interposing";
    951 
    952 // Disables support for Core Animation plugins. This is triggered when
    953 // accelerated compositing is disabled. See http://crbug.com/122430 .
    954 const char kDisableCoreAnimationPlugins[] =
    955     "disable-core-animation-plugins";
    956 #endif
    957 
    958 #if defined(OS_WIN)
    959 // Device scale factor passed to certain processes like renderers, etc.
    960 const char kDeviceScaleFactor[]     = "device-scale-factor";
    961 
    962 // Disables the DirectWrite font rendering system on windows.
    963 const char kDisableDirectWrite[]             = "disable-direct-write";
    964 
    965 // Disable the Legacy Window which corresponds to the size of the WebContents.
    966 const char kDisableLegacyIntermediateWindow[] = "disable-legacy-window";
    967 
    968 // Use high resolution timers for TimeTicks.
    969 const char kEnableHighResolutionTime[]      = "enable-high-resolution-time";
    970 
    971 // Enable the Win32K process mitigation policy for renderer processes which
    972 // prevents them from invoking user32 and gdi32 system calls which enter
    973 // the kernel. This is only supported on Windows 8 and beyond.
    974 const char kEnableWin32kRendererLockDown[]
    975     = "enable_win32k_renderer_lockdown";
    976 #endif
    977 
    978 // Don't dump stuff here, follow the same order as the header.
    979 
    980 }  // namespace switches
    981