src/third_party/WebKit/Source/core/frame/UseCounter.h

   1 /*
   2  * Copyright (C) 2012 Google, Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY GOOGLE INC. ``AS IS'' AND ANY
  14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
  17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #ifndef UseCounter_h
  27 #define UseCounter_h
  28
  29 #include "core/CSSPropertyNames.h"
  30 #include "wtf/BitVector.h"
  31 #include "wtf/Noncopyable.h"
  32 #include "wtf/OwnPtr.h"
  33 #include "wtf/PassOwnPtr.h"
  34 #include "wtf/text/WTFString.h"
  35
  36 namespace blink {
  37
  38 class CSSStyleSheet;
  39 class LocalDOMWindow;
  40 class Document;
  41 class ExecutionContext;
  42 class StyleSheetContents;
  43
  44 // UseCounter is used for counting the number of times features of
  45 // Blink are used on real web pages and help us know commonly
  46 // features are used and thus when it's safe to remove or change them.
  47 //
  48 // The Chromium Content layer controls what is done with this data.
  49 // For instance, in Google Chrome, these counts are submitted
  50 // anonymously through the Histogram recording system in Chrome
  51 // for users who opt-in to "Usage Statistics" submission
  52 // during their install of Google Chrome:
  53 // http://www.google.com/chrome/intl/en/privacy.html
  54
  55 class UseCounter {
  56     WTF_MAKE_NONCOPYABLE(UseCounter);
  57 public:
  58     UseCounter();
  59     ~UseCounter();
  60
  61     enum Feature {
  62         // Do not change assigned numbers of existing items: add new features
  63         // to the end of the list.
  64         PageDestruction = 0,
  65         PrefixedIndexedDB = 3,
  66         WorkerStart = 4,
  67         SharedWorkerStart = 5,
  68         UnprefixedIndexedDB = 9,
  69         OpenWebDatabase = 10,
  70         UnprefixedRequestAnimationFrame = 13,
  71         PrefixedRequestAnimationFrame = 14,
  72         ContentSecurityPolicy = 15,
  73         ContentSecurityPolicyReportOnly = 16,
  74         PrefixedTransitionEndEvent = 18,
  75         UnprefixedTransitionEndEvent = 19,
  76         PrefixedAndUnprefixedTransitionEndEvent = 20,
  77         AutoFocusAttribute = 21,
  78         DataListElement = 23,
  79         FormAttribute = 24,
  80         IncrementalAttribute = 25,
  81         InputTypeColor = 26,
  82         InputTypeDate = 27,
  83         InputTypeDateTimeFallback = 29,
  84         InputTypeDateTimeLocal = 30,
  85         InputTypeEmail = 31,
  86         InputTypeMonth = 32,
  87         InputTypeNumber = 33,
  88         InputTypeRange = 34,
  89         InputTypeSearch = 35,
  90         InputTypeTel = 36,
  91         InputTypeTime = 37,
  92         InputTypeURL = 38,
  93         InputTypeWeek = 39,
  94         InputTypeWeekFallback = 40,
  95         ListAttribute = 41,
  96         MaxAttribute = 42,
  97         MinAttribute = 43,
  98         PatternAttribute = 44,
  99         PlaceholderAttribute = 45,
 100         PrefixedDirectoryAttribute = 47,
 101         RequiredAttribute = 49,
 102         ResultsAttribute = 50,
 103         StepAttribute = 51,
 104         PageVisits = 52,
 105         HTMLMarqueeElement = 53,
 106         Reflection = 55,
 107         PrefixedStorageInfo = 57,
 108         XFrameOptions = 58,
 109         XFrameOptionsSameOrigin = 59,
 110         XFrameOptionsSameOriginWithBadAncestorChain = 60,
 111         DeprecatedFlexboxWebContent = 61,
 112         DeprecatedFlexboxChrome = 62,
 113         DeprecatedFlexboxChromeExtension = 63,
 114         UnprefixedPerformanceTimeline = 65,
 115         UnprefixedUserTiming = 67,
 116         WindowEvent = 69,
 117         ContentSecurityPolicyWithBaseElement = 70,
 118         PrefixedMediaAddKey = 71,
 119         PrefixedMediaGenerateKeyRequest = 72,
 120         DocumentClear = 74,
 121         SVGFontElement = 76,
 122         XMLDocument = 77,
 123         XSLProcessingInstruction = 78,
 124         XSLTProcessor = 79,
 125         SVGSwitchElement = 80,
 126         DocumentAll = 83,
 127         FormElement = 84,
 128         DemotedFormElement = 85,
 129         SVGAnimationElement = 90,
 130         KeyboardEventKeyLocation = 91,
 131         LineClamp = 96,
 132         SubFrameBeforeUnloadRegistered = 97,
 133         SubFrameBeforeUnloadFired = 98,
 134         TextReplaceWholeText = 100,
 135         ConsoleMarkTimeline = 102,
 136         CSSPseudoElementUserAgentCustomPseudo = 103,
 137         ElementGetAttributeNode = 107, // Removed from DOM4.
 138         ElementSetAttributeNode = 108, // Removed from DOM4.
 139         ElementRemoveAttributeNode = 109, // Removed from DOM4.
 140         ElementGetAttributeNodeNS = 110, // Removed from DOM4.
 141         DocumentCreateAttribute = 111, // Removed from DOM4.
 142         DocumentCreateAttributeNS = 112, // Removed from DOM4.
 143         DocumentCreateCDATASection = 113, // Removed from DOM4.
 144         DocumentInputEncoding = 114, // Removed from DOM4.
 145         DocumentXMLEncoding = 115, // Removed from DOM4.
 146         DocumentXMLStandalone = 116, // Removed from DOM4.
 147         DocumentXMLVersion = 117, // Removed from DOM4.
 148         NodeIsSameNode = 118, // Removed from DOM4.
 149         NodeNamespaceURI = 120, // Removed from DOM4.
 150         NodeLocalName = 122, // Removed from DOM4.
 151         NavigatorProductSub = 123,
 152         NavigatorVendor = 124,
 153         NavigatorVendorSub = 125,
 154         FileError = 126,
 155         DocumentCharset = 127, // Documented as IE extensions = 0, from KHTML days.
 156         PrefixedAnimationEndEvent = 128,
 157         UnprefixedAnimationEndEvent = 129,
 158         PrefixedAndUnprefixedAnimationEndEvent = 130,
 159         PrefixedAnimationStartEvent = 131,
 160         UnprefixedAnimationStartEvent = 132,
 161         PrefixedAndUnprefixedAnimationStartEvent = 133,
 162         PrefixedAnimationIterationEvent = 134,
 163         UnprefixedAnimationIterationEvent = 135,
 164         PrefixedAndUnprefixedAnimationIterationEvent = 136,
 165         EventReturnValue = 137, // Legacy IE extension.
 166         SVGSVGElement = 138,
 167         InsertAdjacentText = 140,
 168         InsertAdjacentElement = 141,
 169         HasAttributes = 142, // Removed from DOM4.
 170         DOMSubtreeModifiedEvent = 143,
 171         DOMNodeInsertedEvent = 144,
 172         DOMNodeRemovedEvent = 145,
 173         DOMNodeRemovedFromDocumentEvent = 146,
 174         DOMNodeInsertedIntoDocumentEvent = 147,
 175         DOMCharacterDataModifiedEvent = 148,
 176         DocumentAllLegacyCall = 150,
 177         HTMLAppletElementLegacyCall = 151,
 178         HTMLEmbedElementLegacyCall = 152,
 179         HTMLObjectElementLegacyCall = 153,
 180         GetMatchedCSSRules = 155,
 181         SVGFontInCSS = 156,
 182         AttributeOwnerElement = 160, // Removed in DOM4.
 183         AttributeSpecified = 162, // Removed in DOM4.
 184         PrefixedAudioDecodedByteCount = 164,
 185         PrefixedVideoDecodedByteCount = 165,
 186         PrefixedVideoSupportsFullscreen = 166,
 187         PrefixedVideoDisplayingFullscreen = 167,
 188         PrefixedVideoEnterFullscreen = 168,
 189         PrefixedVideoExitFullscreen = 169,
 190         PrefixedVideoEnterFullScreen = 170,
 191         PrefixedVideoExitFullScreen = 171,
 192         PrefixedVideoDecodedFrameCount = 172,
 193         PrefixedVideoDroppedFrameCount = 173,
 194         PrefixedElementRequestFullscreen = 176,
 195         PrefixedElementRequestFullScreen = 177,
 196         BarPropLocationbar = 178,
 197         BarPropMenubar = 179,
 198         BarPropPersonalbar = 180,
 199         BarPropScrollbars = 181,
 200         BarPropStatusbar = 182,
 201         BarPropToolbar = 183,
 202         InputTypeEmailMultiple = 184,
 203         InputTypeEmailMaxLength = 185,
 204         InputTypeEmailMultipleMaxLength = 186,
 205         InputTypeText = 190,
 206         InputTypeTextMaxLength = 191,
 207         InputTypePassword = 192,
 208         InputTypePasswordMaxLength = 193,
 209         ShowModalDialog = 195,
 210         PrefixedPageVisibility = 196,
 211         CSSStyleSheetInsertRuleOptionalArg = 198, // Inconsistent with the specification and other browsers.
 212         DocumentBeforeUnloadRegistered = 200,
 213         DocumentBeforeUnloadFired = 201,
 214         DocumentUnloadRegistered = 202,
 215         DocumentUnloadFired = 203,
 216         SVGLocatableNearestViewportElement = 204,
 217         SVGLocatableFarthestViewportElement = 205,
 218         HTMLHeadElementProfile = 207,
 219         OverflowChangedEvent = 208,
 220         SVGPointMatrixTransform = 209,
 221         DOMFocusInOutEvent = 211,
 222         FileGetLastModifiedDate = 212,
 223         HTMLElementInnerText = 213,
 224         HTMLElementOuterText = 214,
 225         ReplaceDocumentViaJavaScriptURL = 215,
 226         ElementSetAttributeNodeNS = 216, // Removed from DOM4.
 227         ElementPrefixedMatchesSelector = 217,
 228         CSSStyleSheetRules = 219,
 229         CSSStyleSheetAddRule = 220,
 230         CSSStyleSheetRemoveRule = 221,
 231         // The above items are available in M33 branch.
 232
 233         InitMessageEvent = 222,
 234         ElementSetPrefix = 224, // Element.prefix is readonly in DOM4.
 235         CSSStyleDeclarationGetPropertyCSSValue = 225,
 236         PrefixedMediaCancelKeyRequest = 229,
 237         DOMImplementationHasFeature = 230,
 238         DOMImplementationHasFeatureReturnFalse = 231,
 239         CanPlayTypeKeySystem = 232,
 240         PrefixedDevicePixelRatioMediaFeature = 233,
 241         PrefixedMaxDevicePixelRatioMediaFeature = 234,
 242         PrefixedMinDevicePixelRatioMediaFeature = 235,
 243         PrefixedTransform3dMediaFeature = 237,
 244         PrefixedStorageQuota = 240,
 245         ContentSecurityPolicyReportOnlyInMeta = 241,
 246         ResetReferrerPolicy = 243,
 247         CaseInsensitiveAttrSelectorMatch = 244, // Case-insensitivity dropped from specification.
 248         FormNameAccessForImageElement = 246,
 249         FormNameAccessForPastNamesMap = 247,
 250         FormAssociationByParser = 248,
 251         SVGSVGElementInDocument = 250,
 252         SVGDocumentRootElement = 251,
 253         MediaErrorEncrypted = 253,
 254         EventSourceURL = 254,
 255         WebSocketURL = 255,
 256         WorkerSubjectToCSP = 257,
 257         WorkerAllowedByChildBlockedByScript = 258,
 258         DeprecatedWebKitGradient = 260,
 259         DeprecatedWebKitLinearGradient = 261,
 260         DeprecatedWebKitRepeatingLinearGradient = 262,
 261         DeprecatedWebKitRadialGradient = 263,
 262         DeprecatedWebKitRepeatingRadialGradient = 264,
 263         PrefixedImageSmoothingEnabled = 267,
 264         UnprefixedImageSmoothingEnabled = 268,
 265         // The above items are available in M34 branch.
 266
 267         TextAutosizing = 274,
 268         HTMLAnchorElementPingAttribute = 276,
 269         InsertAdjacentHTML = 278,
 270         SVGClassName = 279,
 271         HTMLAppletElement = 280,
 272         HTMLMediaElementSeekToFragmentStart = 281,
 273         HTMLMediaElementPauseAtFragmentEnd = 282,
 274         PrefixedWindowURL = 283,
 275         PrefixedWorkerURL = 284, // This didn't work because of crbug.com/376039. Available since M37.
 276         WindowOrientation = 285,
 277         DOMStringListContains = 286,
 278         DocumentCaptureEvents = 287,
 279         DocumentReleaseEvents = 288,
 280         WindowCaptureEvents = 289,
 281         WindowReleaseEvents = 290,
 282         PrefixedGamepad = 291,
 283         ElementAnimateKeyframeListEffectObjectTiming = 292,
 284         ElementAnimateKeyframeListEffectDoubleTiming = 293,
 285         ElementAnimateKeyframeListEffectNoTiming = 294,
 286         DocumentXPathCreateExpression = 295,
 287         DocumentXPathCreateNSResolver = 296,
 288         DocumentXPathEvaluate = 297,
 289         AttrGetValue = 298,
 290         AttrSetValue = 299,
 291         AnimationConstructorKeyframeListEffectObjectTiming = 300,
 292         AnimationConstructorKeyframeListEffectDoubleTiming = 301,
 293         AnimationConstructorKeyframeListEffectNoTiming = 302,
 294         AttrSetValueWithElement = 303,
 295         PrefixedCancelAnimationFrame = 304,
 296         PrefixedCancelRequestAnimationFrame = 305,
 297         NamedNodeMapGetNamedItem = 306,
 298         NamedNodeMapSetNamedItem = 307,
 299         NamedNodeMapRemoveNamedItem = 308,
 300         NamedNodeMapItem = 309,
 301         NamedNodeMapGetNamedItemNS = 310,
 302         NamedNodeMapSetNamedItemNS = 311,
 303         NamedNodeMapRemoveNamedItemNS = 312,
 304         OpenWebDatabaseInWorker = 313, // This didn't work because of crbug.com/376039. Available since M37.
 305         OpenWebDatabaseSyncInWorker = 314, // This didn't work because of crbug.com/376039. Available since M37.
 306         XHRProgressEventPosition = 316,
 307         XHRProgressEventTotalSize = 317,
 308         PrefixedDocumentIsFullscreen = 318,
 309         PrefixedDocumentFullScreenKeyboardInputAllowed = 319,
 310         PrefixedDocumentCurrentFullScreenElement = 320,
 311         PrefixedDocumentCancelFullScreen = 321,
 312         PrefixedDocumentFullscreenEnabled = 322,
 313         PrefixedDocumentFullscreenElement = 323,
 314         PrefixedDocumentExitFullscreen = 324,
 315         // The above items are available in M35 branch.
 316
 317         SVGForeignObjectElement = 325,
 318         SelectionSetPosition = 327,
 319         AnimationPlayerFinishEvent = 328,
 320         SVGSVGElementInXMLDocument = 329,
 321         CanvasRenderingContext2DSetAlpha = 330,
 322         CanvasRenderingContext2DSetCompositeOperation = 331,
 323         CanvasRenderingContext2DSetLineWidth = 332,
 324         CanvasRenderingContext2DSetLineCap = 333,
 325         CanvasRenderingContext2DSetLineJoin = 334,
 326         CanvasRenderingContext2DSetMiterLimit = 335,
 327         CanvasRenderingContext2DClearShadow = 336,
 328         CanvasRenderingContext2DSetStrokeColor = 337,
 329         CanvasRenderingContext2DSetFillColor = 338,
 330         CanvasRenderingContext2DDrawImageFromRect = 339,
 331         CanvasRenderingContext2DSetShadow = 340,
 332         PrefixedPerformanceClearResourceTimings = 341,
 333         PrefixedPerformanceSetResourceTimingBufferSize = 342,
 334         EventSrcElement = 343,
 335         EventCancelBubble = 344,
 336         EventPath = 345,
 337         EventClipboardData = 346,
 338         NodeIteratorDetach = 347,
 339         AttrNodeValue = 348,
 340         AttrTextContent = 349,
 341         EventGetReturnValueTrue = 350,
 342         EventGetReturnValueFalse = 351,
 343         EventSetReturnValueTrue = 352,
 344         EventSetReturnValueFalse = 353,
 345         NodeIteratorExpandEntityReferences = 354,
 346         TreeWalkerExpandEntityReferences = 355,
 347         WindowOffscreenBuffering = 356,
 348         WindowDefaultStatus = 357,
 349         WindowDefaultstatus = 358,
 350         PrefixedTransitionEventConstructor = 361,
 351         PrefixedMutationObserverConstructor = 362,
 352         PrefixedIDBCursorConstructor = 363,
 353         PrefixedIDBDatabaseConstructor = 364,
 354         PrefixedIDBFactoryConstructor = 365,
 355         PrefixedIDBIndexConstructor = 366,
 356         PrefixedIDBKeyRangeConstructor = 367,
 357         PrefixedIDBObjectStoreConstructor = 368,
 358         PrefixedIDBRequestConstructor = 369,
 359         PrefixedIDBTransactionConstructor = 370,
 360         NotificationPermission = 371,
 361         RangeDetach = 372,
 362         HTMLTableElementVspace = 374,
 363         HTMLTableElementHspace = 375,
 364         PrefixedTouchRadiusX = 378,
 365         PrefixedTouchRadiusY = 379,
 366         PrefixedTouchRotationAngle = 380,
 367         PrefixedTouchForce = 381,
 368         PrefixedMouseEventMovementX = 382,
 369         PrefixedMouseEventMovementY = 383,
 370         PrefixedFileRelativePath = 386,
 371         DocumentCaretRangeFromPoint = 387,
 372         DocumentGetCSSCanvasContext = 388,
 373         ElementScrollIntoViewIfNeeded = 389,
 374         RangeCompareNode = 392,
 375         RangeExpand = 393,
 376         HTMLImageElementX = 396,
 377         HTMLImageElementY = 397,
 378         SelectionBaseNode = 400,
 379         SelectionBaseOffset = 401,
 380         SelectionExtentNode = 402,
 381         SelectionExtentOffset = 403,
 382         SelectionType = 404,
 383         SelectionModify = 405,
 384         SelectionSetBaseAndExtent = 406,
 385         SelectionEmpty = 407,
 386         VTTCue = 409,
 387         VTTCueRender = 410,
 388         VTTCueRenderVertical = 411,
 389         VTTCueRenderSnapToLinesFalse = 412,
 390         VTTCueRenderLineNotAuto = 413,
 391         VTTCueRenderPositionNot50 = 414,
 392         VTTCueRenderSizeNot100 = 415,
 393         VTTCueRenderAlignNotMiddle = 416,
 394         // The above items are available in M36 branch.
 395
 396         ElementRequestPointerLock = 417,
 397         VTTCueRenderRtl = 418,
 398         PostMessageFromSecureToInsecure = 419,
 399         PostMessageFromInsecureToSecure = 420,
 400         DocumentExitPointerLock = 421,
 401         DocumentPointerLockElement = 422,
 402         PrefixedCursorZoomIn = 424,
 403         PrefixedCursorZoomOut = 425,
 404         CSSCharsetRuleEncoding = 426,
 405         DocumentSetCharset = 427,
 406         DocumentDefaultCharset = 428,
 407         TextEncoderConstructor = 429,
 408         TextEncoderEncode = 430,
 409         TextDecoderConstructor = 431,
 410         TextDecoderDecode = 432,
 411         FocusInOutEvent = 433,
 412         MouseEventMovementX = 434,
 413         MouseEventMovementY = 435,
 414         MixedContentRaw = 437,
 415         MixedContentImage = 438,
 416         MixedContentMedia = 439,
 417         DocumentFonts = 440,
 418         MixedContentFormsSubmitted = 441,
 419         FormsSubmitted = 442,
 420         TextInputEventOnInput = 443,
 421         TextInputEventOnTextArea = 444,
 422         TextInputEventOnContentEditable = 445,
 423         TextInputEventOnNotNode = 446,
 424         WebkitBeforeTextInsertedOnInput = 447,
 425         WebkitBeforeTextInsertedOnTextArea = 448,
 426         WebkitBeforeTextInsertedOnContentEditable = 449,
 427         WebkitBeforeTextInsertedOnNotNode = 450,
 428         WebkitEditableContentChangedOnInput = 451,
 429         WebkitEditableContentChangedOnTextArea = 452,
 430         WebkitEditableContentChangedOnContentEditable = 453,
 431         WebkitEditableContentChangedOnNotNode = 454,
 432         HTMLImports = 455,
 433         ElementCreateShadowRoot = 456,
 434         DocumentRegisterElement = 457,
 435         EditingAppleInterchangeNewline = 458,
 436         EditingAppleConvertedSpace = 459,
 437         EditingApplePasteAsQuotation = 460,
 438         EditingAppleStyleSpanClass = 461,
 439         EditingAppleTabSpanClass = 462,
 440         HTMLImportsAsyncAttribute = 463,
 441         FontFaceSetReady = 464,
 442         XMLHttpRequestSynchronous = 465,
 443         CSSSelectorPseudoUnresolved = 466,
 444         CSSSelectorPseudoShadow = 467,
 445         CSSSelectorPseudoContent = 468,
 446         CSSSelectorPseudoHost = 469,
 447         CSSSelectorPseudoHostContext = 470,
 448         CSSDeepCombinator = 471,
 449         SyncXHRWithCredentials = 472,
 450         // The above items are available in M37 branch.
 451
 452         UseAsm = 473,
 453         KeyEventNotAllowedInFullScreen = 474,
 454         DOMWindowOpen = 475,
 455         DOMWindowOpenFeatures = 476,
 456         MediaStreamTrackGetSources = 478,
 457         AspectRatioFlexItem = 479,
 458         DetailsElement = 480,
 459         DialogElement = 481,
 460         MapElement = 482,
 461         MeterElement = 483,
 462         ProgressElement = 484,
 463         VideoFullscreenAllowedExemption = 485,
 464         WebKitPoint = 488,
 465         PrefixedHTMLElementDropzone = 490,
 466         WheelEventWheelDeltaX = 491,
 467         WheelEventWheelDeltaY = 492,
 468         WheelEventWheelDelta = 493,
 469         SendBeacon = 494,
 470         SendBeaconQuotaExceeded = 495,
 471         SVGSMILElementInDocument = 501,
 472         MouseEventOffsetX = 502,
 473         MouseEventOffsetY = 503,
 474         MouseEventX = 504,
 475         MouseEventY = 505,
 476         MouseEventFromElement = 506,
 477         MouseEventToElement = 507,
 478         RequestFileSystem = 508,
 479         RequestFileSystemWorker = 509,
 480         RequestFileSystemSyncWorker = 510,
 481         UIEventLayerX = 511,
 482         UIEventLayerY = 512,
 483         UIEventPageX = 513,
 484         UIEventPageY = 514,
 485         BgPropertiesFixed = 515,
 486         HTMLImageElementComposite = 516,
 487         DevToolsConsoleTimeline = 517,
 488         DevToolsConsoleProfile = 518,
 489         SVGStyleElementTitle = 519,
 490         PictureSourceSrc = 520,
 491         // Add new features immediately above this line. Don't change assigned
 492         // numbers of any item, and don't reuse removed slots.
 493         // Also, run update_use_counter_feature_enum.py in chromium/src/tools/metrics/histograms/
 494         // to update the UMA mapping.
 495         NumberOfFeatures, // This enum value must be last.
 496     };
 497
 498     // "count" sets the bit for this feature to 1. Repeated calls are ignored.
 499     static void count(const Document&, Feature);
 500     // This doesn't count for ExecutionContexts for shared workers and service
 501     // workers.
 502     static void count(const ExecutionContext*, Feature);
 503     void count(CSSParserContext, CSSPropertyID);
 504     void count(Feature);
 505
 506     // "countDeprecation" sets the bit for this feature to 1, and sends a deprecation
 507     // warning to the console. Repeated calls are ignored.
 508     //
 509     // Be considerate to developers' consoles: features should only send
 510     // deprecation warnings when we're actively interested in removing them from
 511     // the platform.
 512     //
 513     // The ExecutionContext* overload doesn't work for shared workers and
 514     // service workers.
 515     static void countDeprecation(const LocalDOMWindow*, Feature);
 516     static void countDeprecation(ExecutionContext*, Feature);
 517     static void countDeprecation(const Document&, Feature);
 518     String deprecationMessage(Feature);
 519
 520     void didCommitLoad();
 521
 522     static UseCounter* getFrom(const Document*);
 523     static UseCounter* getFrom(const CSSStyleSheet*);
 524     static UseCounter* getFrom(const StyleSheetContents*);
 525
 526     static int mapCSSPropertyIdToCSSSampleIdForHistogram(int id);
 527
 528     static void muteForInspector();
 529     static void unmuteForInspector();
 530
 531 private:
 532     static int m_muteCount;
 533
 534     bool recordMeasurement(Feature feature)
 535     {
 536         if (UseCounter::m_muteCount)
 537             return false;
 538         ASSERT(feature != PageDestruction); // PageDestruction is reserved as a scaling factor.
 539         ASSERT(feature < NumberOfFeatures);
 540         if (!m_countBits) {
 541             m_countBits = adoptPtr(new BitVector(NumberOfFeatures));
 542             m_countBits->clearAll();
 543         }
 544
 545         if (m_countBits->quickGet(feature))
 546             return false;
 547
 548         m_countBits->quickSet(feature);
 549         return true;
 550     }
 551
 552     void updateMeasurements();
 553
 554     OwnPtr<BitVector> m_countBits;
 555     BitVector m_CSSFeatureBits;
 556 };
 557
 558 } // namespace blink
 559
 560 #endif // UseCounter_h