Convert Settings.in, CSSValueKeywords.in, SVGCSSValueKeywords.in to json5

third_party/WebKit/Source/core/frame/Settings.json5

+{
+// Defines properties which are available on the Settings object.
+//
+// Please think carefully before adding a new Setting.  Some questions to
+// consider are:
+// - Should this be a RuntimeEnabledFeature instead? Settings are for things
+//   which we support either values of at runtime.  Features are set at renderer
+//   process startup and are never changed. Features also tend to be set to a
+//   value based on the platform or the stability of the code in question, where
+//   as settings both codepaths need to be stable.
+// - How will you ensure test coverage of all relevant values of your setting?
+// - Is the default value appropriate for other platforms or ports which may
+//   not be aware of your setting?
+// - Can your setting result in behavior differences observable to web
+//   developers?
+// - Should this setting ideally be removed in the future?  If so please file
+//   a bug and reference it in the comments for your setting.
+//
+// One reason to add a Setting is to manage the risk associated with adding a
+// new feature.  For example, we may choose to ship a new UI behavior or
+// performance optimization to ChromeOS users first (in order to gather feedback
+// and metrics on its use from the wild) before attempting to ship it to
+// Windows.
+//
+// FIXME: Add support for global settings.
+// FIXME: Add support for custom getters/setters.
+
+// Valid parameters for data entries below.
+parameters: {
+    type: {
+        default: "bool"
+    },
+    initial: {},
+    invalidate: {},
+},
+
+data: [
+  {
+    name: "defaultTextEncodingName",
+    type: "String",
+  },
+
+  // Do not hide chars typed in password fields immediately, but let the last char stay
+  // visible for N seconds, configured by the passwordEchoDurationInSeconds setting
+  // FIXME: Enable automatically if passwordEchoDurationInSeconds is set to a positive value.
+  {
+    name: "passwordEchoEnabled",
+    initial: false,
+  },
+
+  // Configure how long the last char should say visible in seconds.
+  {
+    name: "passwordEchoDurationInSeconds",
+    initial: 1,
+    type: "double",
+  },
+
+  // Sets the magnification value for validation message timer.  If the
+  // magnification value is N, a validation message disappears automatically after
+  // <message length> * N / 1000 seconds.  If N is equal to or less than 0, a
+  // validation message doesn't disappears automaticaly.
+  {
+    name: "validationMessageTimerMagnification",
+    initial: 50,
+    type: "int",
+  },
+
+  // Number of pixels below which 2D canvas is rendered in software
+  // even if hardware acceleration is enabled.
+  // Hardware acceleration is useful for large canvases where it can avoid the
+  // pixel bandwidth between the CPU and GPU. But GPU acceleration comes at
+  // a price - extra back-buffer and texture copy. Small canvases are also
+  // widely used for stylized fonts. Anti-aliasing text in hardware at that
+  // scale is generally slower. So below a certain size it is better to
+  // draw canvas in software.
+  {
+    name: "minimumAccelerated2dCanvasSize",
+    initial: "257*256",
+    type: "int",
+  },
+
+  {
+    name: "minimumFontSize",
+    initial: 0,
+    invalidate: "Style",
+    type: "int",
+  },
+  {
+    name: "minimumLogicalFontSize",
+    initial: 0,
+    invalidate: "Style",
+    type: "int",
+  },
+  {
+    name: "defaultFontSize",
+    initial: 0,
+    invalidate: "Style",
+    type: "int",
+  },
+  {
+    name: "defaultFixedFontSize",
+    initial: 0,
+    invalidate: "Style",
+    type: "int",
+  },
+
+  {
+    name: "editingBehaviorType",
+    initial: "editingBehaviorTypeForPlatform()",
+    type: "EditingBehaviorType",
+  },
+
+  {
+    name: "localStorageEnabled",
+    initial: false,
+  },
+  {
+    name: "allowUniversalAccessFromFileURLs",
+    initial: true,
+  },
+  {
+    name: "allowFileAccessFromFileURLs",
+    initial: true,
+  },
+  {
+    name: "javaScriptCanOpenWindowsAutomatically",
+    initial: false,
+  },
+  {
+    name: "supportsMultipleWindows",
+    initial: true,
+  },
+  {
+    name: "javaScriptCanAccessClipboard",
+    initial: false,
+  },
+  {
+    name: "shouldPrintBackgrounds",
+    initial: false,
+  },
+  {
+    name: "shouldClearDocumentBackground",
+    initial: true,
+  },
+
+  {
+    name: "textAreasAreResizable",
+    initial: false,
+    invalidate: "Style",
+  },
+  {
+    name: "acceleratedCompositingEnabled",
+    initial: true,
+    invalidate: "AcceleratedCompositing",
+  },
+
+  {
+    name: "offlineWebApplicationCacheEnabled",
+    initial: true,
+  },
+  {
+    name: "allowScriptsToCloseWindows",
+    initial: false,
+  },
+
+  // FIXME: This should really be disabled by default as it makes platforms that
+  // don't support the feature download files they can't use by.
+  // Leaving enabled for now to not change existing behavior.
+  {
+    name: "downloadableBinaryFontsEnabled",
+    initial: true,
+  },
+
+  {
+    name: "xssAuditorEnabled",
+    initial: false,
+  },
+
+  {
+    name: "preferCompositingToLCDTextEnabled",
+    initial: false,
+    invalidate: "AcceleratedCompositing",
+  },
+
+  // 3D canvas (WebGL) support.
+  {
+    name: "webGLEnabled",
+    initial: false,
+  },
+
+  {
+    name: "webGLErrorsToConsoleEnabled",
+    initial: true,
+  },
+  {
+    name: "antialiased2dCanvasEnabled",
+    initial: true,
+  },
+  {
+    name: "antialiasedClips2dCanvasEnabled",
+    initial: true,
+  },
+  {
+    name: "accelerated2dCanvasMSAASampleCount",
+    initial: 0,
+    type: "int",
+  },
+
+  {
+    name: "hyperlinkAuditingEnabled",
+    initial: false,
+  },
+  {
+    name: "allowRunningOfInsecureContent",
+    initial: true,
+  },
+
+  {
+    name: "mediaControlsOverlayPlayButtonEnabled",
+    initial: false,
+  },
+  {
+    name: "mediaPlaybackRequiresUserGesture",
+    initial: false,
+  },
+
+  // This flags overrides mediaPlaybackRequiresUserGesture
+  {
+    name: "crossOriginMediaPlaybackRequiresUserGesture",
+    initial: false,
+  },
+
+  {
+    name: "presentationRequiresUserGesture",
+    initial: true,
+  },
+
+  {
+    name: "scrollAnimatorEnabled",
+    initial: true,
+  },
+
+  // Used to disable threaded, compositor scrolling for testing purposes.
+  // crbug.com/410974 tracks removal once alternative solutions for selective
+  // main thread scrolling are supported.
+  {
+    name: "threadedScrollingEnabled",
+    initial: true,
+    invalidate: "Style",
+  },
+
+  // Used in layout tests for gesture tap highlights. Makes the highlights square
+  // (rather than rounded) to make it possible to reftest the results.
+  {
+    name: "mockGestureTapHighlightsEnabled",
+    initial: false,
+  },
+
+  {
+    name: "shouldRespectImageOrientation",
+    initial: false,
+  },
+
+  // Limited use by features which behave differently depending on the input
+  // devices available.  For example, the pointer and hover media queries.
+  // Note that we need to be careful when basing behavior or UI on this -
+  // just because a device is present doesn't mean the user cares about it
+  // or uses it (i.e. Chromebook Pixel users generally don't want to give up
+  // screen real estate just because they happen to have a touchscreen).
+  {
+    name: "deviceSupportsTouch",
+    initial: false,
+  },
+
+  // This value indicates the number of simultaneous multi-touch points supported
+  // by the currently connected screen/digitizer that supports the most points.
+  // From Pointer Events spec:
+  //   http://www.w3.org/TR/pointerevents///widl-Navigator-maxTouchPoints
+  {
+    name: "maxTouchPoints",
+    initial: 0,
+    type: "int",
+  },
+
+  // Whether touch gestures should be "fuzzed" to nearest touch targets.
+  // It's expected that this is enabled everywhere by default, but it may be
+  // disabled for testing purposes as the algorithm is not yet perfect.
+  // crbug.com/304895 tracks removal once we're satisfied with the algorithm.
+  {
+    name: "touchAdjustmentEnabled",
+    initial: true,
+  },
+
+  // Determines whether WebViewClient::didTapMultipleTargets will be used for
+  // touch disambiguation.
+  {
+    name: "multiTargetTapNotificationEnabled",
+    initial: true,
+  },
+
+  {
+    name: "syncXHRInDocumentsEnabled",
+    initial: true,
+  },
+  {
+    name: "cookieEnabled",
+    initial: true,
+  },
+  {
+    name: "navigateOnDragDrop",
+    initial: true,
+  },
+  {
+    name: "DOMPasteAllowed",
+    initial: false,
+  },
+
+  {
+    name: "allowCustomScrollbarInMainFrame",
+    initial: true,
+  },
+  {
+    name: "webSecurityEnabled",
+    initial: true,
+  },
+
+  // Special keyboard navigation mode intented for platforms with no
+  // proper mouse or touch support, such as a TV controller with a remote.
+  {
+    name: "spatialNavigationEnabled",
+    initial: false,
+  },
+
+  // This setting adds a means to enable/disable touch initiated drag & drop. If
+  // enabled, the user can initiate drag using long press.
+  // crbug.com/304894 tracks removal once it's been enabled on all platforms.
+  {
+    name: "touchDragDropEnabled",
+    initial: false,
+  },
+
+  // Some apps could have a default video poster if it is not set.
+  {
+    name: "defaultVideoPosterURL",
+    type: "String",
+  },
+
+  {
+    name: "smartInsertDeleteEnabled",
+    initial: false,
+  },
+  {
+    name: "selectTrailingWhitespaceEnabled",
+    initial: "defaultSelectTrailingWhitespaceEnabled",
+  },
+
+  {
+    name: "selectionIncludesAltImageText",
+    initial: false,
+  },
+
+  {
+    name: "selectionStrategy",
+    initial: "SelectionStrategy::Character",
+    type: "SelectionStrategy",
+  },
+
+  //////////////// Settings used by Android WebView below ////////////////
+
+  {
+    name: "useLegacyBackgroundSizeShorthandBehavior",
+    initial: false,
+  },
+
+  // This quirk is to maintain compatibility with Android apps built on
+  // the Android SDK prior to and including version 18.
+  // Presumably, this can be removed any time after 2015.
+  // See http://crbug.com/282130.
+  {
+    name: "viewportMetaZeroValuesQuirk",
+    initial: false,
+  },
+
+  // Another Android SDK <= 18 quirk, removable 2015.
+  // See http://crbug.com/295287
+  {
+    name: "ignoreMainFrameOverflowHiddenQuirk",
+    initial: false,
+  },
+
+  // Yet another Android SDK <= 18 quirk, removable 2015.
+  // See http://crbug.com/305236
+  {
+    name: "reportScreenSizeInPhysicalPixelsQuirk",
+    initial: false,
+  },
+
+  // One more Android SDK <= 18 quirk, removable 2015.
+  // See http://crbug.com/306548
+  {
+    name: "viewportMetaMergeContentQuirk",
+    initial: false,
+  },
+
+  // This quirk is to maintain compatibility with Android apps.
+  // It will be possible to remove it once WebSettings.{get|set}UseWideViewPort
+  // API function will be removed.
+  // See http://crbug.com/288037.
+  {
+    name: "wideViewportQuirkEnabled",
+    initial: false,
+  },
+
+  // Used by the android_webview to support a horizontal height auto-sizing
+  // mode.
+  {
+    name: "forceZeroLayoutHeight",
+    initial: false,
+    invalidate: "ViewportDescription",
+  },
+
+  {
+    name: "mainFrameClipsContent",
+    initial: true,
+  },
+
+  // For android.webkit.WebSettings.setUseWideViewport()
+  // http://developer.android.com/reference/android/webkit/WebSettings.html//setUseWideViewPort(boolean)
+  {
+    name: "useWideViewport",
+    initial: true,
+    invalidate: "ViewportDescription",
+  },
+
+  // For android.webkit.WebSettings.setLoadWithOverviewMode()
+  // http://developer.android.com/reference/android/webkit/WebSettings.html//setLoadWithOverviewMode(boolean)
+  {
+    name: "loadWithOverviewMode",
+    initial: true,
+    invalidate: "ViewportDescription",
+  },
+
+  // Used by android_webview to support legacy apps that inject script into a top-level initial empty
+  // document and expect it to persist on navigation, even though the origin is unique. Note that this
+  // behavior violates the requirements described by [Initialising a new Document object] in
+  // https://html.spec.whatwg.org/multipage/browsers.html//navigating-across-documents.
+  {
+    name: "shouldReuseGlobalForUnownedMainFrame",
+    initial: false,
+  },
+
+  //////////////// End of settings used by Android WebView ////////////////
+
+
+  // Touch based text selection and editing on desktop.
+  // crbug.com/304873 tracks removal once it's been enabled on all platforms.
+  {
+    name: "touchEditingEnabled",
+    initial: false,
+  },
+
+  // If true, scrollers will use overlay scrollbars.  These do not take up any
+  // layout width, are drawn using solid color quads by the compositor, and fade away
+  // after a timeout.
+  {
+    name: "useSolidColorScrollbars",
+    initial: false,
+  },
+
+  // Experiment to have all APIs reflect the layout viewport.
+  // crbug.com/489206 tracks the experiment.
+  {
+    name: "inertVisualViewport",
+    initial: false,
+  },
+
+  // The rubber-band overscroll effect is implemented in Blink and is being moved
+  // to the compositor thread. This will be set to true and eventually removed.
+  // crbug.com/133097
+  {
+    name: "rubberBandingOnCompositorThread",
+    initial: false,
+  },
+
+  // Font scale factor for accessibility, applied as part of text autosizing.
+  {
+    name: "accessibilityFontScaleFactor",
+    initial: "1.0",
+    invalidate: "TextAutosizing",
+    type: "double",
+  },
+
+  // Only used by Layout Tests and inspector emulation.
+  {
+    name: "mediaTypeOverride",
+    initial: "\"\"",
+    invalidate: "MediaQuery",
+    type: "String",
+  },
+  {
+    name: "displayModeOverride",
+    initial: "WebDisplayModeUndefined",
+    invalidate: "MediaQuery",
+    type: "WebDisplayMode",
+  },
+
+  // loadsImagesAutomatically only suppresses the network load of
+  // the image URL. A cached image will still be rendered if requested.
+  {
+    name: "loadsImagesAutomatically",
+    initial: false,
+    invalidate: "ImageLoading",
+  },
+  {
+    name: "imagesEnabled",
+    initial: true,
+    invalidate: "ImageLoading",
+  },
+  {
+    name: "imageAnimationPolicy",
+    initial: "ImageAnimationPolicyAllowed",
+    type: "ImageAnimationPolicy",
+  },
+
+  // Number of outstanding and pending tokens allowed in the background HTML
+  // parser. A value of 0 indicates the parser should use its default value.
+  {
+    name: "backgroundHtmlParserOutstandingTokenLimit",
+    initial: 0,
+    type: "unsigned",
+  },
+  {
+    name: "backgroundHtmlParserPendingTokenLimit",
+    initial: 0,
+    type: "unsigned",
+  },
+
+  // Html preload scanning is a fast, early scan of HTML documents to find loadable
+  // resources before the parser advances to them. If it is disabled, resources will
+  // be loaded later.
+  {
+    name: "doHtmlPreloadScanning",
+    initial: true,
+  },
+
+  {
+    name: "pluginsEnabled",
+    initial: false,
+  },
+
+  {
+    name: "viewportEnabled",
+    initial: false,
+    invalidate: "ViewportDescription",
+  },
+  {
+    name: "viewportMetaEnabled",
+    initial: false,
+    invalidate: "ViewportDescription",
+  },
+
+  {
+    name: "dnsPrefetchingEnabled",
+    initial: false,
+    invalidate: "DNSPrefetching",
+  },
+
+  {
+    name: "dataSaverEnabled",
+    initial: false,
+  },
+
+  // FIXME: This is a temporary flag and should be removed
+  // when squashing is ready. (crbug.com/261605)
+  {
+    name: "layerSquashingEnabled",
+    initial: false,
+  },
+
+  // Clients that execute script should call ScriptController::canExecuteScripts()
+  // instead of this function. ScriptController::canExecuteScripts() checks the
+  // HTML sandbox, plugin sandboxing, and other important details.
+  {
+    name: "scriptEnabled",
+    initial: false,
+  },
+
+  // Forces initialization of main world, even if no scripts will be executed.
+  // Used by inspector to report all contexts.
+  {
+    name: "forceMainWorldInitialization",
+    initial: false,
+    invalidate: "DOMWorlds",
+  },
+
+  // Compensates for poor text legibility on mobile devices. This value is
+  // multiplied by the font scale factor when performing text autosizing of
+  // websites that do not set an explicit viewport description.
+  {
+    name: "deviceScaleAdjustment",
+    initial: "1.0",
+    invalidate: "TextAutosizing",
+    type: "double",
+  },
+
+  // This value indicates the maximum number of bytes a document is allowed to
+  // transmit in Beacons (via navigator.sendBeacon()) -- Beacons are intended to be
+  // smaller payloads transmitted as a page is unloading, not a general (one-way)
+  // network transmission API. The spec <https://w3c.github.io/beacon/> does not
+  // proscribe an upper limit, but allows for it -- the underlying API will return
+  // 'false' in that case.
+  {
+    name: "maxBeaconTransmission",
+    initial: 65536,
+    type: "int",
+  },
+
+  // This value is set to false if the platform does not support fullscreen.
+  // When set to false all the requests to enter fullscreen will return an error
+  // (fullscreenerror or webkitfullscreenerror) as specified in the standard:
+  // http://fullscreen.spec.whatwg.org///dom-element-requestfullscreen
+  {
+    name: "fullscreenSupported",
+    initial: true,
+  },
+
+  // V8 supports different types of caching. Used by V8 bindings.
+  {
+    name: "v8CacheOptions",
+    initial: "V8CacheOptionsDefault",
+    type: "V8CacheOptions",
+  },
+
+  // V8 code cache for CacheStorage supports three types of strategies (none, normal and aggressive).
+  {
+    name: "v8CacheStrategiesForCacheStorage",
+    initial: "V8CacheStrategiesForCacheStorage::Default",
+    type: "V8CacheStrategiesForCacheStorage",
+  },
+
+  // These values are bit fields for the properties of available pointing devices
+  // and may take on multiple values (e.g. laptop with touchpad and touchscreen
+  // has pointerType coarse *and* fine).
+  {
+    name: "availablePointerTypes",
+    initial: "PointerTypeNone",
+    invalidate: "MediaQuery",
+    type: "int",
+  },
+  {
+    name: "availableHoverTypes",
+    initial: "HoverTypeNone",
+    invalidate: "MediaQuery",
+    type: "int",
+  },
+
+  // These values specify properties of the user's primary pointing device only.
+  {
+    name: "primaryPointerType",
+    initial: "PointerTypeNone",
+    invalidate: "MediaQuery",
+    type: "PointerType",
+  },
+  {
+    name: "primaryHoverType",
+    initial: "HoverTypeNone",
+    invalidate: "MediaQuery",
+    type: "HoverType",
+  },
+
+  // Whether accessibility support is enabled at all.
+  {
+    name: "accessibilityEnabled",
+    initial: false,
+    invalidate: "AccessibilityState",
+  },
+
+  // If true, the value in password fields is exposed to assistive technologies.
+  {
+    name: "accessibilityPasswordValuesEnabled",
+    initial: false,
+  },
+
+  // If true, static text nodes expose inline text box children.
+  {
+    name: "inlineTextBoxAccessibilityEnabled",
+    initial: false,
+  },
+
+  // If true, context menu will be shown on mouse up instead of mouse down.
+  // Typically enabled on Windows to match platform convention.
+  {
+    name: "showContextMenuOnMouseUp",
+    initial: false,
+  },
+
+  // If true, context menu will be shown on any long press event.
+  // Used on Android to prevent a context menu from being shown in certain situations
+  // (i.e. long pressing an empty div)
+  {
+    name: "alwaysShowContextMenuOnTouch",
+    initial: true,
+  },
+
+  {
+    name: "disableReadingFromCanvas",
+    initial: false,
+  },
+  {
+    name: "strictMixedContentChecking",
+    initial: false,
+  },
+  {
+    name: "strictMixedContentCheckingForPlugin",
+    initial: false,
+  },
+  {
+    name: "strictPowerfulFeatureRestrictions",
+    initial: false,
+  },
+  {
+    name: "strictlyBlockBlockableMixedContent",
+    initial: false,
+  },
+  {
+    name: "allowGeolocationOnInsecureOrigins",
+    initial: false,
+  },
+  {
+    name: "logDnsPrefetchAndPreconnect",
+    initial: false,
+  },
+  {
+    name: "logPreload",
+    initial: false,
+  },
+
+  // These values specify the UA intial viewport style.
+  // It is dynamically set by the inspector for mobile emulation and can be
+  // used by content embedders to specify custom style on certain platforms.
+  {
+    name: "viewportStyle",
+    initial: "WebViewportStyle::Default",
+    invalidate: "ViewportRule",
+    type: "WebViewportStyle",
+  },
+
+  // Automatic track selection is performed based on user preference for track kind specified
+  // by this setting.
+  {
+    name: "textTrackKindUserPreference",
+    initial: "TextTrackKindUserPreference::Default",
+    invalidate: "TextTrackKindUserPreference",
+    type: "TextTrackKindUserPreference",
+  },
+
+  // User style overrides for captions and subtitles
+  {
+    name: "textTrackBackgroundColor",
+    type: "String",
+  },
+  {
+    name: "textTrackFontFamily",
+    type: "String",
+  },
+  {
+    name: "textTrackFontStyle",
+    type: "String",
+  },
+  {
+    name: "textTrackFontVariant",
+    type: "String",
+  },
+  {
+    name: "textTrackTextColor",
+    type: "String",
+  },
+  {
+    name: "textTrackTextShadow",
+    type: "String",
+  },
+  {
+    name: "textTrackTextSize",
+    type: "String",
+  },
+
+  // Margin for title-safe placement of cues with overscan, gives top and bottom margin size as
+  // percentage of video element height (for horizontal text) into which cues will not be placed.
+  {
+    name: "textTrackMarginPercentage",
+    initial: 0,
+    type: "double",
+  },
+
+  {
+    name: "lowPriorityIframes",
+    initial: false,
+  },
+
+  {
+    name: "progressBarCompletion",
+    initial: "ProgressBarCompletion::LoadEvent",
+    type: "ProgressBarCompletion",
+  },
+
+  {
+    name: "historyEntryRequiresUserGesture",
+    initial: false,
+  },
+
+  // Do we want to try to save screen real estate in the media player by hiding
+  // the volume slider / mute button?
+  {
+    name: "preferHiddenVolumeControls",
+    initial: false,
+  },
+
+  // Whether to disallow network fetches for parser blocking scripts in the main
+  // frame inserted via document.write, for users on 2G or connections that are
+  // effectively 2G.
+  {
+    name: "disallowFetchForDocWrittenScriptsInMainFrameIfEffectively2G",
+    initial: false,
+  },
+
+  // Whether to disallow network fetches for parser blocking scripts in the main
+  // frame inserted via document.write, for users on slow connections.
+  {
+    name: "disallowFetchForDocWrittenScriptsInMainFrameOnSlowConnections",
+    initial: false,
+  },
+
+  // Whether to disallow network fetches for parser blocking scripts in the main
+  // frame inserted via document.write, regardless of connection type.
+  {
+    name: "disallowFetchForDocWrittenScriptsInMainFrame",
+    initial: false,
+  },
+
+  // Whether to invalidate device-dependent media queries and restore scroll positions
+  // on frame resize assuming device rotation.
+  {
+    name: "mainFrameResizesAreOrientationChanges",
+    initial: false,
+  },
+
+  // Ability to override the default 'passive' value in AddEventListenerOptions. This
+  // is useful to demonstrate the power of passive event listeners. This can be removed
+  // when there is greater adoption, interventions to force it on and associated devtools
+  // to enable it have been shipped.
+  {
+    name: "passiveListenerDefault",
+    initial: "PassiveListenerDefault::False",
+    type: "PassiveListenerDefault",
+  },
+
+  // Use default interpolation quality to scale bitmap images if quality is not determined
+  // in other ways. This can help us writing reftests containing scaled images.
+  {
+    name: "useDefaultImageInterpolationQuality",
+    initial: false,
+  },
+
+  // Variant of the ParseHTMLOnMainThread experiment. One experiment immediately
+  // tokenizes input bytes. The default is to tokenize with a post task.
+  {
+    name: "parseHTMLOnMainThreadSyncTokenize",
+    initial: false,
+  },
+
+  // Variant of the ParseHTMLOnMainThread experiment. This is designed to coalesce
+  // TokenizedChunks when the experiment is running in threaded mode.
+  {
+    name: "parseHTMLOnMainThreadCoalesceChunks",
+    initial: false,
+  },
+
+  // Whether the CSSPreloadScanner is used for externally CSS preloads. NoPreload
+  // indicates that the scanner will be used, but no preloads issued.
+  {
+    name: "cssExternalScannerNoPreload",
+    initial: false,
+  },
+  {
+    name: "cssExternalScannerPreload",
+    initial: false,
+  },
+
+  {
+    name: "browserSideNavigationEnabled",
+    initial: false,
+  },
+
+  // Some platforms have media subsystems which are too buggy to allow preloading
+  // of content by default. See http://crbug.com/612909 for details.
+  {
+    name: "forcePreloadNoneForMediaElements",
+    initial: false,
+  },
+
+  {
+    name: "hideScrollbars",
+    initial: false,
+  },
+
+  // Spellchecking is enabled by default for elements that do not specify it explicitly
+  // using the "spellcheck" attribute.
+  {
+    name: "spellCheckEnabledByDefault",
+    initial: true,
+  },
+
+  // Whether download UI should be hidden for the current page content.
+  {
+    name: "hideDownloadUI",
+    initial: false,
+  },
+
+  // Whether or not to issue range requests for images and show placeholders.
+  {
+    name: "fetchImagePlaceholders",
+    initial: false,
+  },
+
+  // Whether the frame is a presentation receiver and should expose
+  // `navigator.presentation.receiver`.
+  {
+    name: "presentationReceiver",
+    initial: false,
+  },
+]
+}