/*
 * Copyright (C) 2012 Google, Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY GOOGLE INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef UseCounter_h
#define UseCounter_h

#include "core/CSSPropertyNames.h"
#include "core/CoreExport.h"
#include "core/css/parser/CSSParserMode.h"
#include "platform/heap/GarbageCollected.h"
#include "platform/heap/HeapAllocator.h"
#include "platform/weborigin/KURL.h"
#include "platform/wtf/BitVector.h"
#include "platform/wtf/Noncopyable.h"
#include "platform/wtf/text/WTFString.h"
#include "v8/include/v8.h"

namespace blink {

class CSSStyleSheet;
class Document;
class EnumerationHistogram;
class ExecutionContext;
class Frame;
class StyleSheetContents;

// UseCounter is used for counting the number of times features of
// Blink are used on real web pages and help us know commonly
// features are used and thus when it's safe to remove or change them.
//
// The Chromium Content layer controls what is done with this data.
//
// For instance, in Google Chrome, these counts are submitted anonymously
// through the UMA histogram recording system in Chrome for users who have the
// "Automatically send usage statistics and crash reports to Google" setting
// enabled:
// http://www.google.com/chrome/intl/en/privacy.html
//
// Changes on UseCounter are observable by UseCounter::Observer.
class CORE_EXPORT UseCounter {
  DISALLOW_NEW();
  WTF_MAKE_NONCOPYABLE(UseCounter);

 public:
  enum Context {
    kDefaultContext,
    // Counters for SVGImages (lifetime independent from other pages).
    kSVGImageContext,
    // Counters for extensions.
    kExtensionContext,
    // Context when counters should be disabled (eg, internal pages such as
    // about, chrome-devtools, etc).
    kDisabledContext
  };

  UseCounter(Context = kDefaultContext);

  enum Feature : uint32_t {
    // Do not change assigned numbers of existing items: add new features
    // to the end of the list.
    kOBSOLETE_PageDestruction = 0,
    kWorkerStart = 4,
    kSharedWorkerStart = 5,
    kUnprefixedIndexedDB = 9,
    kOpenWebDatabase = 10,
    kUnprefixedRequestAnimationFrame = 13,
    kPrefixedRequestAnimationFrame = 14,
    kContentSecurityPolicy = 15,
    kContentSecurityPolicyReportOnly = 16,
    kPrefixedTransitionEndEvent = 18,
    kUnprefixedTransitionEndEvent = 19,
    kPrefixedAndUnprefixedTransitionEndEvent = 20,
    kAutoFocusAttribute = 21,
    kDataListElement = 23,
    kFormAttribute = 24,
    kIncrementalAttribute = 25,
    kInputTypeColor = 26,
    kInputTypeDate = 27,
    kInputTypeDateTimeFallback = 29,
    kInputTypeDateTimeLocal = 30,
    kInputTypeEmail = 31,
    kInputTypeMonth = 32,
    kInputTypeNumber = 33,
    kInputTypeRange = 34,
    kInputTypeSearch = 35,
    kInputTypeTel = 36,
    kInputTypeTime = 37,
    kInputTypeURL = 38,
    kInputTypeWeek = 39,
    kInputTypeWeekFallback = 40,
    kListAttribute = 41,
    kMaxAttribute = 42,
    kMinAttribute = 43,
    kPatternAttribute = 44,
    kPlaceholderAttribute = 45,
    kPrefixedDirectoryAttribute = 47,
    kRequiredAttribute = 49,
    kStepAttribute = 51,
    kPageVisits = 52,
    kHTMLMarqueeElement = 53,
    kReflection = 55,
    kPrefixedStorageInfo = 57,
    kDeprecatedFlexboxWebContent = 61,
    kDeprecatedFlexboxChrome = 62,
    kDeprecatedFlexboxChromeExtension = 63,
    kUnprefixedPerformanceTimeline = 65,
    kUnprefixedUserTiming = 67,
    kWindowEvent = 69,
    kContentSecurityPolicyWithBaseElement = 70,
    kDocumentClear = 74,
    kXMLDocument = 77,
    kXSLProcessingInstruction = 78,
    kXSLTProcessor = 79,
    kSVGSwitchElement = 80,
    kDocumentAll = 83,
    kFormElement = 84,
    kDemotedFormElement = 85,
    kSVGAnimationElement = 90,
    kLineClamp = 96,
    kSubFrameBeforeUnloadRegistered = 97,
    kSubFrameBeforeUnloadFired = 98,
    kConsoleMarkTimeline = 102,
    kDocumentCreateAttribute = 111,
    kDocumentCreateAttributeNS = 112,
    kDocumentXMLEncoding = 115,    // Removed from DOM4.
    kDocumentXMLStandalone = 116,  // Removed from DOM4.
    kDocumentXMLVersion = 117,     // Removed from DOM4.
    kNavigatorProductSub = 123,
    kNavigatorVendor = 124,
    kNavigatorVendorSub = 125,
    kPrefixedAnimationEndEvent = 128,
    kUnprefixedAnimationEndEvent = 129,
    kPrefixedAndUnprefixedAnimationEndEvent = 130,
    kPrefixedAnimationStartEvent = 131,
    kUnprefixedAnimationStartEvent = 132,
    kPrefixedAndUnprefixedAnimationStartEvent = 133,
    kPrefixedAnimationIterationEvent = 134,
    kUnprefixedAnimationIterationEvent = 135,
    kPrefixedAndUnprefixedAnimationIterationEvent = 136,
    kEventReturnValue = 137,  // Legacy IE extension.
    kSVGSVGElement = 138,
    kDOMSubtreeModifiedEvent = 143,
    kDOMNodeInsertedEvent = 144,
    kDOMNodeRemovedEvent = 145,
    kDOMNodeRemovedFromDocumentEvent = 146,
    kDOMNodeInsertedIntoDocumentEvent = 147,
    kDOMCharacterDataModifiedEvent = 148,
    kDocumentAllLegacyCall = 150,
    kGetMatchedCSSRules = 155,
    kPrefixedAudioDecodedByteCount = 164,
    kPrefixedVideoDecodedByteCount = 165,
    kPrefixedVideoSupportsFullscreen = 166,
    kPrefixedVideoDisplayingFullscreen = 167,
    kPrefixedVideoEnterFullscreen = 168,
    kPrefixedVideoExitFullscreen = 169,
    kPrefixedVideoEnterFullScreen = 170,
    kPrefixedVideoExitFullScreen = 171,
    kPrefixedVideoDecodedFrameCount = 172,
    kPrefixedVideoDroppedFrameCount = 173,
    kPrefixedElementRequestFullscreen = 176,
    kPrefixedElementRequestFullScreen = 177,
    kBarPropLocationbar = 178,
    kBarPropMenubar = 179,
    kBarPropPersonalbar = 180,
    kBarPropScrollbars = 181,
    kBarPropStatusbar = 182,
    kBarPropToolbar = 183,
    kInputTypeEmailMultiple = 184,
    kInputTypeEmailMaxLength = 185,
    kInputTypeEmailMultipleMaxLength = 186,
    kInputTypeText = 190,
    kInputTypeTextMaxLength = 191,
    kInputTypePassword = 192,
    kInputTypePasswordMaxLength = 193,
    kPrefixedPageVisibility = 196,
    kDocumentBeforeUnloadRegistered = 200,
    kDocumentBeforeUnloadFired = 201,
    kDocumentUnloadRegistered = 202,
    kDocumentUnloadFired = 203,
    kSVGLocatableNearestViewportElement = 204,
    kSVGLocatableFarthestViewportElement = 205,
    kSVGPointMatrixTransform = 209,
    kDOMFocusInOutEvent = 211,
    kFileGetLastModifiedDate = 212,
    kHTMLElementInnerText = 213,
    kHTMLElementOuterText = 214,
    kReplaceDocumentViaJavaScriptURL = 215,
    kElementPrefixedMatchesSelector = 217,
    kCSSStyleSheetRules = 219,
    kCSSStyleSheetAddRule = 220,
    kCSSStyleSheetRemoveRule = 221,
    // The above items are available in M33 branch.

    kInitMessageEvent = 222,
    kPrefixedDevicePixelRatioMediaFeature = 233,
    kPrefixedMaxDevicePixelRatioMediaFeature = 234,
    kPrefixedMinDevicePixelRatioMediaFeature = 235,
    kPrefixedTransform3dMediaFeature = 237,
    kPrefixedStorageQuota = 240,
    kResetReferrerPolicy = 243,
    // Case-insensitivity dropped from specification.
    kCaseInsensitiveAttrSelectorMatch = 244,
    kFormNameAccessForImageElement = 246,
    kFormNameAccessForPastNamesMap = 247,
    kFormAssociationByParser = 248,
    kSVGSVGElementInDocument = 250,
    kSVGDocumentRootElement = 251,
    kWorkerSubjectToCSP = 257,
    kWorkerAllowedByChildBlockedByScript = 258,
    kDeprecatedWebKitGradient = 260,
    kDeprecatedWebKitLinearGradient = 261,
    kDeprecatedWebKitRepeatingLinearGradient = 262,
    kDeprecatedWebKitRadialGradient = 263,
    kDeprecatedWebKitRepeatingRadialGradient = 264,
    // The above items are available in M34 branch.

    kTextAutosizing = 274,
    kHTMLAnchorElementPingAttribute = 276,
    kSVGClassName = 279,
    kHTMLMediaElementSeekToFragmentStart = 281,
    kHTMLMediaElementPauseAtFragmentEnd = 282,
    kPrefixedWindowURL = 283,
    kWindowOrientation = 285,
    kDocumentCaptureEvents = 287,
    kDocumentReleaseEvents = 288,
    kWindowCaptureEvents = 289,
    kWindowReleaseEvents = 290,
    kDocumentXPathCreateExpression = 295,
    kDocumentXPathCreateNSResolver = 296,
    kDocumentXPathEvaluate = 297,
    kAnimationConstructorKeyframeListEffectObjectTiming = 300,
    kAnimationConstructorKeyframeListEffectNoTiming = 302,
    kPrefixedCancelAnimationFrame = 304,
    kNamedNodeMapGetNamedItem = 306,
    kNamedNodeMapSetNamedItem = 307,
    kNamedNodeMapRemoveNamedItem = 308,
    kNamedNodeMapItem = 309,
    kNamedNodeMapGetNamedItemNS = 310,
    kNamedNodeMapSetNamedItemNS = 311,
    kNamedNodeMapRemoveNamedItemNS = 312,
    kPrefixedDocumentIsFullscreen = 318,
    kPrefixedDocumentCurrentFullScreenElement = 320,
    kPrefixedDocumentCancelFullScreen = 321,
    kPrefixedDocumentFullscreenEnabled = 322,
    kPrefixedDocumentFullscreenElement = 323,
    kPrefixedDocumentExitFullscreen = 324,
    // The above items are available in M35 branch.

    kSVGForeignObjectElement = 325,
    kSelectionSetPosition = 327,
    kAnimationFinishEvent = 328,
    kSVGSVGElementInXMLDocument = 329,
    kEventSrcElement = 343,
    kEventCancelBubble = 344,
    kEventPath = 345,
    kNodeIteratorDetach = 347,
    kEventGetReturnValueTrue = 350,
    kEventGetReturnValueFalse = 351,
    kEventSetReturnValueTrue = 352,
    kEventSetReturnValueFalse = 353,
    kWindowOffscreenBuffering = 356,
    kWindowDefaultStatus = 357,
    kWindowDefaultstatus = 358,
    kPrefixedTransitionEventConstructor = 361,
    kPrefixedMutationObserverConstructor = 362,
    kNotificationPermission = 371,
    kRangeDetach = 372,
    kPrefixedFileRelativePath = 386,
    kDocumentCaretRangeFromPoint = 387,
    kElementScrollIntoViewIfNeeded = 389,
    kRangeExpand = 393,
    kHTMLImageElementX = 396,
    kHTMLImageElementY = 397,
    kSelectionBaseNode = 400,
    kSelectionBaseOffset = 401,
    kSelectionExtentNode = 402,
    kSelectionExtentOffset = 403,
    kSelectionType = 404,
    kSelectionModify = 405,
    kSelectionSetBaseAndExtent = 406,
    kSelectionEmpty = 407,
    kVTTCue = 409,
    kVTTCueRender = 410,
    kVTTCueRenderVertical = 411,
    kVTTCueRenderSnapToLinesFalse = 412,
    kVTTCueRenderLineNotAuto = 413,
    kVTTCueRenderPositionNot50 = 414,
    kVTTCueRenderSizeNot100 = 415,
    kVTTCueRenderAlignNotCenter = 416,
    // The above items are available in M36 branch.

    kElementRequestPointerLock = 417,
    kVTTCueRenderRtl = 418,
    kPostMessageFromSecureToInsecure = 419,
    kPostMessageFromInsecureToSecure = 420,
    kDocumentExitPointerLock = 421,
    kDocumentPointerLockElement = 422,
    kPrefixedCursorZoomIn = 424,
    kPrefixedCursorZoomOut = 425,
    kTextEncoderConstructor = 429,
    kTextEncoderEncode = 430,
    kTextDecoderConstructor = 431,
    kTextDecoderDecode = 432,
    kFocusInOutEvent = 433,
    kMouseEventMovementX = 434,
    kMouseEventMovementY = 435,
    kDocumentFonts = 440,
    kMixedContentFormsSubmitted = 441,
    kFormsSubmitted = 442,
    kHTMLImports = 455,
    kElementCreateShadowRoot = 456,
    kDocumentRegisterElement = 457,
    kEditingAppleInterchangeNewline = 458,
    kEditingAppleConvertedSpace = 459,
    kEditingApplePasteAsQuotation = 460,
    kEditingAppleStyleSpanClass = 461,
    kHTMLImportsAsyncAttribute = 463,
    kXMLHttpRequestSynchronous = 465,
    kCSSSelectorPseudoUnresolved = 466,
    kCSSSelectorPseudoShadow = 467,
    kCSSSelectorPseudoContent = 468,
    kCSSSelectorPseudoHost = 469,
    kCSSSelectorPseudoHostContext = 470,
    kCSSDeepCombinator = 471,
    // The above items are available in M37 branch.

    kUseAsm = 473,
    kDOMWindowOpen = 475,
    kDOMWindowOpenFeatures = 476,
    kAspectRatioFlexItem = 479,
    kDetailsElement = 480,
    kDialogElement = 481,
    kMapElement = 482,
    kMeterElement = 483,
    kProgressElement = 484,
    kWheelEventWheelDeltaX = 491,
    kWheelEventWheelDeltaY = 492,
    kWheelEventWheelDelta = 493,
    kSendBeacon = 494,
    kSendBeaconQuotaExceeded = 495,
    kSVGSMILElementInDocument = 501,
    kMouseEventOffsetX = 502,
    kMouseEventOffsetY = 503,
    kMouseEventX = 504,
    kMouseEventY = 505,
    kMouseEventFromElement = 506,
    kMouseEventToElement = 507,
    kRequestFileSystem = 508,
    kRequestFileSystemWorker = 509,
    kRequestFileSystemSyncWorker = 510,
    kSVGStyleElementTitle = 519,
    kPictureSourceSrc = 520,
    // The above items are available in M38 branch.

    kPicture = 521,
    kSizes = 522,
    kSrcsetXDescriptor = 523,
    kSrcsetWDescriptor = 524,
    kSelectionContainsNode = 525,
    kXMLExternalResourceLoad = 529,
    kMixedContentPrivateHostnameInPublicHostname = 530,
    kLegacyProtocolEmbeddedAsSubresource = 531,
    kRequestedSubresourceWithEmbeddedCredentials = 532,
    kNotificationCreated = 533,
    kNotificationClosed = 534,
    kNotificationPermissionRequested = 535,
    kConsoleTimeline = 538,
    kConsoleTimelineEnd = 539,
    kSRIElementWithMatchingIntegrityAttribute = 540,
    kSRIElementWithNonMatchingIntegrityAttribute = 541,
    kSRIElementWithUnparsableIntegrityAttribute = 542,
    kV8Animation_StartTime_AttributeGetter = 545,
    kV8Animation_StartTime_AttributeSetter = 546,
    kV8Animation_CurrentTime_AttributeGetter = 547,
    kV8Animation_CurrentTime_AttributeSetter = 548,
    kV8Animation_PlaybackRate_AttributeGetter = 549,
    kV8Animation_PlaybackRate_AttributeSetter = 550,
    kV8Animation_PlayState_AttributeGetter = 551,
    kV8Animation_Finish_Method = 552,
    kV8Animation_Play_Method = 553,
    kV8Animation_Pause_Method = 554,
    kV8Animation_Reverse_Method = 555,
    // The above items are available in M39 branch.

    kBreakIterator = 556,
    kScreenOrientationAngle = 557,
    kScreenOrientationType = 558,
    kScreenOrientationLock = 559,
    kScreenOrientationUnlock = 560,
    kGeolocationSecureOrigin = 561,
    kGeolocationInsecureOrigin = 562,
    kNotificationSecureOrigin = 563,
    kNotificationInsecureOrigin = 564,
    kNotificationShowEvent = 565,
    kSVGTransformListConsolidate = 569,
    kSVGAnimatedTransformListBaseVal = 570,
    kQuotedAnimationName = 571,
    kQuotedKeyframesRule = 572,
    kSrcsetDroppedCandidate = 573,
    kWindowPostMessage = 574,
    kRenderRuby = 576,
    kScriptElementWithInvalidTypeHasSrc = 578,
    kXMLHttpRequestSynchronousInNonWorkerOutsideBeforeUnload = 581,
    kCSSSelectorPseudoScrollbar = 582,
    kCSSSelectorPseudoScrollbarButton = 583,
    kCSSSelectorPseudoScrollbarThumb = 584,
    kCSSSelectorPseudoScrollbarTrack = 585,
    kCSSSelectorPseudoScrollbarTrackPiece = 586,
    kLangAttribute = 587,
    kLangAttributeOnHTML = 588,
    kLangAttributeOnBody = 589,
    kLangAttributeDoesNotMatchToUILocale = 590,
    kInputTypeSubmit = 591,
    kInputTypeSubmitWithValue = 592,
    // The above items are available in M40 branch.

    kSetReferrerPolicy = 593,
    kTextWholeText = 599,
    kNotificationCloseEvent = 603,
    kStyleMedia = 606,
    kStyleMediaType = 607,
    kStyleMediaMatchMedium = 608,
    kMixedContentPresent = 609,
    kMixedContentBlockable = 610,
    kMixedContentAudio = 611,
    kMixedContentDownload = 612,
    kMixedContentFavicon = 613,
    kMixedContentImage = 614,
    kMixedContentInternal = 615,
    kMixedContentPlugin = 616,
    kMixedContentPrefetch = 617,
    kMixedContentVideo = 618,
    kCSSSelectorPseudoFullScreenAncestor = 628,
    kCSSSelectorPseudoFullScreen = 629,
    kWebKitCSSMatrix = 630,
    kAudioContextCreateAnalyser = 631,
    kAudioContextCreateBiquadFilter = 632,
    kAudioContextCreateBufferSource = 633,
    kAudioContextCreateChannelMerger = 634,
    kAudioContextCreateChannelSplitter = 635,
    kAudioContextCreateConvolver = 636,
    kAudioContextCreateDelay = 637,
    kAudioContextCreateDynamicsCompressor = 638,
    kAudioContextCreateGain = 639,
    kAudioContextCreateMediaElementSource = 640,
    kAudioContextCreateMediaStreamDestination = 641,
    kAudioContextCreateMediaStreamSource = 642,
    kAudioContextCreateOscillator = 643,
    kAudioContextCreatePeriodicWave = 645,
    kAudioContextCreateScriptProcessor = 646,
    kAudioContextCreateStereoPanner = 647,
    kAudioContextCreateWaveShaper = 648,
    kAudioContextDecodeAudioData = 649,
    kAudioContextResume = 650,
    kAudioContextSuspend = 651,
    kMixedContentInNonHTTPSFrameThatRestrictsMixedContent = 661,
    kMixedContentInSecureFrameThatDoesNotRestrictMixedContent = 662,
    kMixedContentWebSocket = 663,
    kSyntheticKeyframesInCompositedCSSAnimation = 664,
    kMixedContentFormPresent = 665,
    kGetUserMediaInsecureOrigin = 666,
    kGetUserMediaSecureOrigin = 667,
    // The above items are available in M41 branch.

    kDeviceMotionInsecureOrigin = 668,
    kDeviceMotionSecureOrigin = 669,
    kDeviceOrientationInsecureOrigin = 670,
    kDeviceOrientationSecureOrigin = 671,
    kSandboxViaIFrame = 672,
    kSandboxViaCSP = 673,
    kBlockedSniffingImageToScript = 674,
    kFetch = 675,
    kFetchBodyStream = 676,
    kXMLHttpRequestAsynchronous = 677,
    kWhiteSpacePreFromXMLSpace = 679,
    kWhiteSpaceNowrapFromXMLSpace = 680,
    kSVGSVGElementForceRedraw = 685,
    kSVGSVGElementSuspendRedraw = 686,
    kSVGSVGElementUnsuspendRedraw = 687,
    kSVGSVGElementUnsuspendRedrawAll = 688,
    kAudioContextClose = 689,
    kCSSZoomNotEqualToOne = 691,
    // The above items are available in M42 branch.

    kClientRectListItem = 694,
    kWindowClientInformation = 695,
    kWindowFind = 696,
    kWindowScreenLeft = 697,
    kWindowScreenTop = 698,
    kV8Animation_Cancel_Method = 699,
    kV8Animation_Onfinish_AttributeGetter = 700,
    kV8Animation_Onfinish_AttributeSetter = 701,
    kV8Window_WebKitAnimationEvent_ConstructorGetter = 707,
    kCryptoGetRandomValues = 710,
    kSubtleCryptoEncrypt = 711,
    kSubtleCryptoDecrypt = 712,
    kSubtleCryptoSign = 713,
    kSubtleCryptoVerify = 714,
    kSubtleCryptoDigest = 715,
    kSubtleCryptoGenerateKey = 716,
    kSubtleCryptoImportKey = 717,
    kSubtleCryptoExportKey = 718,
    kSubtleCryptoDeriveBits = 719,
    kSubtleCryptoDeriveKey = 720,
    kSubtleCryptoWrapKey = 721,
    kSubtleCryptoUnwrapKey = 722,
    kCryptoAlgorithmAesCbc = 723,
    kCryptoAlgorithmHmac = 724,
    kCryptoAlgorithmRsaSsaPkcs1v1_5 = 725,
    kCryptoAlgorithmSha1 = 726,
    kCryptoAlgorithmSha256 = 727,
    kCryptoAlgorithmSha384 = 728,
    kCryptoAlgorithmSha512 = 729,
    kCryptoAlgorithmAesGcm = 730,
    kCryptoAlgorithmRsaOaep = 731,
    kCryptoAlgorithmAesCtr = 732,
    kCryptoAlgorithmAesKw = 733,
    kCryptoAlgorithmRsaPss = 734,
    kCryptoAlgorithmEcdsa = 735,
    kCryptoAlgorithmEcdh = 736,
    kCryptoAlgorithmHkdf = 737,
    kCryptoAlgorithmPbkdf2 = 738,
    kDocumentSetDomain = 739,
    kUpgradeInsecureRequestsEnabled = 740,
    kUpgradeInsecureRequestsUpgradedRequest = 741,
    kDocumentDesignMode = 742,
    kGlobalCacheStorage = 743,
    kNetInfo = 744,
    kBackgroundSync = 745,
    kLegacyConst = 748,
    kV8Permissions_Query_Method = 750,
    // The above items are available in M43 branch.

    kV8HTMLInputElement_Autocapitalize_AttributeGetter = 754,
    kV8HTMLInputElement_Autocapitalize_AttributeSetter = 755,
    kV8HTMLTextAreaElement_Autocapitalize_AttributeGetter = 756,
    kV8HTMLTextAreaElement_Autocapitalize_AttributeSetter = 757,
    kSVGHrefBaseVal = 758,
    kSVGHrefAnimVal = 759,
    kV8CSSRuleList_Item_Method = 760,
    kV8MediaList_Item_Method = 761,
    kV8StyleSheetList_Item_Method = 762,
    kStyleSheetListAnonymousNamedGetter = 763,
    kAutocapitalizeAttribute = 764,
    kFullscreenSecureOrigin = 765,
    kFullscreenInsecureOrigin = 766,
    kDialogInSandboxedContext = 767,
    kSVGSMILAnimationInImageRegardlessOfCache = 768,
    kPerformanceFrameTiming = 772,
    kV8Element_Animate_Method = 773,
    // The above items are available in M44 branch.

    kV8SVGSVGElement_GetElementById_Method = 778,
    kElementCreateShadowRootMultiple = 779,
    kV8MessageChannel_Constructor = 780,
    kV8MessagePort_PostMessage_Method = 781,
    kV8MessagePort_Start_Method = 782,
    kV8MessagePort_Close_Method = 783,
    kMessagePortsTransferred = 784,
    kCSSKeyframesRuleAnonymousIndexedGetter = 785,
    kV8Screen_AvailLeft_AttributeGetter = 786,
    kV8Screen_AvailTop_AttributeGetter = 787,
    kV8SVGFEConvolveMatrixElement_PreserveAlpha_AttributeGetter = 791,
    kV8SVGStyleElement_Disabled_AttributeGetter = 798,
    kV8SVGStyleElement_Disabled_AttributeSetter = 799,
    kInputTypeFileSecureOrigin = 801,
    kInputTypeFileInsecureOrigin = 802,
    kElementAttachShadow = 804,
    kV8SecurityPolicyViolationEvent_DocumentURI_AttributeGetter = 806,
    kV8SecurityPolicyViolationEvent_BlockedURI_AttributeGetter = 807,
    kV8SecurityPolicyViolationEvent_StatusCode_AttributeGetter = 808,
    kHTMLLinkElementDisabled = 809,
    kV8HTMLLinkElement_Disabled_AttributeGetter = 810,
    kV8HTMLLinkElement_Disabled_AttributeSetter = 811,
    kV8HTMLStyleElement_Disabled_AttributeGetter = 812,
    kV8HTMLStyleElement_Disabled_AttributeSetter = 813,
    kV8DOMError_Constructor = 816,
    kV8DOMError_Name_AttributeGetter = 817,
    kV8DOMError_Message_AttributeGetter = 818,
    kTextInputFired = 830,
    kV8TextEvent_Data_AttributeGetter = 831,
    kV8TextEvent_InitTextEvent_Method = 832,
    kClientHintsDPR = 835,
    kClientHintsResourceWidth = 836,
    kClientHintsViewportWidth = 837,
    kSRIElementIntegrityAttributeButIneligible = 838,
    kFormDataAppendNull = 843,
    kNonHTMLElementSetAttributeNodeFromHTMLDocumentNameNotLowercase = 845,
    kNavigatorVibrate = 850,
    kNavigatorVibrateSubFrame = 851,
    kV8XPathEvaluator_Constructor = 853,
    kV8XPathEvaluator_CreateExpression_Method = 854,
    kV8XPathEvaluator_CreateNSResolver_Method = 855,
    kV8XPathEvaluator_Evaluate_Method = 856,
    kRequestMIDIAccess = 857,
    kV8MouseEvent_LayerX_AttributeGetter = 858,
    kV8MouseEvent_LayerY_AttributeGetter = 859,
    kInnerTextWithShadowTree = 860,
    kSelectionToStringWithShadowTree = 861,
    kWindowFindWithShadowTree = 862,
    kV8CompositionEvent_InitCompositionEvent_Method = 863,
    kV8CustomEvent_InitCustomEvent_Method = 864,
    kV8DeviceMotionEvent_InitDeviceMotionEvent_Method = 865,
    kV8DeviceOrientationEvent_InitDeviceOrientationEvent_Method = 866,
    kV8Event_InitEvent_Method = 867,
    kV8KeyboardEvent_InitKeyboardEvent_Method = 868,
    kV8MouseEvent_InitMouseEvent_Method = 869,
    kV8MutationEvent_InitMutationEvent_Method = 870,
    kV8StorageEvent_InitStorageEvent_Method = 871,
    kV8UIEvent_InitUIEvent_Method = 873,
    kV8Document_CreateTouch_Method = 874,
    kRequestFileSystemNonWebbyOrigin = 876,
    kV8MemoryInfo_TotalJSHeapSize_AttributeGetter = 879,
    kV8MemoryInfo_UsedJSHeapSize_AttributeGetter = 880,
    kV8MemoryInfo_JSHeapSizeLimit_AttributeGetter = 881,
    kV8Performance_Timing_AttributeGetter = 882,
    kV8Performance_Navigation_AttributeGetter = 883,
    kV8Performance_Memory_AttributeGetter = 884,
    kV8SharedWorker_WorkerStart_AttributeGetter = 885,
    // The above items are available in M45 branch.

    kHTMLMediaElementPreloadNone = 892,
    kHTMLMediaElementPreloadMetadata = 893,
    kHTMLMediaElementPreloadAuto = 894,
    kHTMLMediaElementPreloadDefault = 895,
    kMixedContentBlockableAllowed = 896,
    kPseudoBeforeAfterForInputElement = 897,
    kV8Permissions_Revoke_Method = 898,
    kLinkRelDnsPrefetch = 899,
    kLinkRelPreconnect = 900,
    kLinkRelPreload = 901,
    kLinkHeaderDnsPrefetch = 902,
    kLinkHeaderPreconnect = 903,
    kClientHintsMetaAcceptCH = 904,
    kHTMLElementDeprecatedWidth = 905,
    kClientHintsContentDPR = 906,
    kElementAttachShadowOpen = 907,
    kElementAttachShadowClosed = 908,
    kAudioParamSetValueAtTime = 909,
    kAudioParamLinearRampToValueAtTime = 910,
    kAudioParamExponentialRampToValueAtTime = 911,
    kAudioParamSetTargetAtTime = 912,
    kAudioParamSetValueCurveAtTime = 913,
    kAudioParamCancelScheduledValues = 914,
    kV8Permissions_Request_Method = 915,
    kLinkRelPrefetch = 917,
    kLinkRelPrerender = 918,
    kLinkRelNext = 919,
    kCSSValuePrefixedMinContent = 921,
    kCSSValuePrefixedMaxContent = 922,
    kCSSValuePrefixedFitContent = 923,
    kCSSValuePrefixedFillAvailable = 924,
    kPresentationDefaultRequest = 926,
    kPresentationAvailabilityChangeEventListener = 927,
    kPresentationRequestConstructor = 928,
    kPresentationRequestStart = 929,
    kPresentationRequestReconnect = 930,
    kPresentationRequestGetAvailability = 931,
    kPresentationRequestConnectionAvailableEventListener = 932,
    kPresentationConnectionTerminate = 933,
    kPresentationConnectionSend = 934,
    kPresentationConnectionMessageEventListener = 936,
    kCSSAnimationsStackedNeutralKeyframe = 937,
    kReadingCheckedInClickHandler = 938,
    kFlexboxIntrinsicSizeAlgorithmIsDifferent = 939,
    // The above items are available in M46 branch.

    kHTMLImportsHasStyleSheets = 940,
    kNetInfoType = 946,
    kNetInfoDownlinkMax = 947,
    kNetInfoOnChange = 948,
    kNetInfoOnTypeChange = 949,
    kV8Window_Alert_Method = 950,
    kV8Window_Confirm_Method = 951,
    kV8Window_Prompt_Method = 952,
    kV8Window_Print_Method = 953,
    kV8Window_RequestIdleCallback_Method = 954,
    kFlexboxPercentagePaddingVertical = 955,
    kFlexboxPercentageMarginVertical = 956,
    kBackspaceNavigatedBack = 957,
    kBackspaceNavigatedBackAfterFormInteraction = 958,
    kCSPSourceWildcardWouldMatchExactHost = 959,
    kCredentialManagerGet = 960,
    kCredentialManagerGetMediationOptional = 961,
    kCredentialManagerGetMediationSilent = 962,
    kCredentialManagerStore = 963,
    kCredentialManagerRequireUserMediation = 964,
    // The above items are available in M47 branch.

    kBlockableMixedContentInSubframeBlocked = 966,
    kAddEventListenerThirdArgumentIsObject = 967,
    kRemoveEventListenerThirdArgumentIsObject = 968,
    kCSSAtRuleCharset = 969,
    kCSSAtRuleFontFace = 970,
    kCSSAtRuleImport = 971,
    kCSSAtRuleKeyframes = 972,
    kCSSAtRuleMedia = 973,
    kCSSAtRuleNamespace = 974,
    kCSSAtRulePage = 975,
    kCSSAtRuleSupports = 976,
    kCSSAtRuleViewport = 977,
    kCSSAtRuleWebkitKeyframes = 978,
    kV8HTMLFieldSetElement_Elements_AttributeGetter = 979,
    kHTMLMediaElementPreloadForcedNone = 980,
    kExternalAddSearchProvider = 981,
    kExternalIsSearchProviderInstalled = 982,
    kV8Permissions_RequestAll_Method = 983,
    kDeviceOrientationAbsoluteInsecureOrigin = 987,
    kDeviceOrientationAbsoluteSecureOrigin = 988,
    kFontFaceConstructor = 989,
    kServiceWorkerControlledPage = 990,
    kMeterElementWithMeterAppearance = 993,
    kMeterElementWithNoneAppearance = 994,
    kSelectionAnchorNode = 997,
    kSelectionAnchorOffset = 998,
    kSelectionFocusNode = 999,
    kSelectionFocusOffset = 1000,
    kSelectionIsCollapsed = 1001,
    kSelectionRangeCount = 1002,
    kSelectionGetRangeAt = 1003,
    kSelectionAddRange = 1004,
    kSelectionRemoveAllRanges = 1005,
    kSelectionCollapse = 1006,
    kSelectionCollapseToStart = 1007,
    kSelectionCollapseToEnd = 1008,
    kSelectionExtend = 1009,
    kSelectionSelectAllChildren = 1010,
    kSelectionDeleteDromDocument = 1011,
    kSelectionDOMString = 1012,
    kInputTypeRangeVerticalAppearance = 1013,
    // The above items are available in M48 branch.

    kCSSFilterReference = 1014,
    kCSSFilterGrayscale = 1015,
    kCSSFilterSepia = 1016,
    kCSSFilterSaturate = 1017,
    kCSSFilterHueRotate = 1018,
    kCSSFilterInvert = 1019,
    kCSSFilterOpacity = 1020,
    kCSSFilterBrightness = 1021,
    kCSSFilterContrast = 1022,
    kCSSFilterBlur = 1023,
    kCSSFilterDropShadow = 1024,
    kBackgroundSyncRegister = 1025,
    kExecCommandOnInputOrTextarea = 1027,
    kV8History_ScrollRestoration_AttributeGetter = 1028,
    kV8History_ScrollRestoration_AttributeSetter = 1029,
    kSVG1DOMFilter = 1030,
    kOfflineAudioContextStartRendering = 1031,
    kOfflineAudioContextSuspend = 1032,
    kOfflineAudioContextResume = 1033,
    kSVG1DOMPaintServer = 1035,
    kSVGSVGElementFragmentSVGView = 1036,
    kSVGSVGElementFragmentSVGViewElement = 1037,
    kPresentationConnectionClose = 1038,
    kSVG1DOMShape = 1039,
    kSVG1DOMText = 1040,
    kRTCPeerConnectionConstructorConstraints = 1041,
    kRTCPeerConnectionConstructorCompliant = 1042,
    kRTCPeerConnectionCreateOfferLegacyFailureCallback = 1044,
    kRTCPeerConnectionCreateOfferLegacyConstraints = 1045,
    kRTCPeerConnectionCreateOfferLegacyOfferOptions = 1046,
    kRTCPeerConnectionCreateOfferLegacyCompliant = 1047,
    kRTCPeerConnectionCreateAnswerLegacyFailureCallback = 1049,
    kRTCPeerConnectionCreateAnswerLegacyConstraints = 1050,
    kRTCPeerConnectionCreateAnswerLegacyCompliant = 1051,
    kRTCPeerConnectionSetLocalDescriptionLegacyNoSuccessCallback = 1052,
    kRTCPeerConnectionSetLocalDescriptionLegacyNoFailureCallback = 1053,
    kRTCPeerConnectionSetLocalDescriptionLegacyCompliant = 1054,
    kRTCPeerConnectionSetRemoteDescriptionLegacyNoSuccessCallback = 1055,
    kRTCPeerConnectionSetRemoteDescriptionLegacyNoFailureCallback = 1056,
    kRTCPeerConnectionSetRemoteDescriptionLegacyCompliant = 1057,
    kRTCPeerConnectionGetStatsLegacyNonCompliant = 1058,
    kNodeFilterIsFunction = 1059,
    kNodeFilterIsObject = 1060,
    kCSSSelectorInternalPseudoListBox = 1062,
    kCSSSelectorInternalMediaControlsOverlayCastButton = 1064,
    kCSSSelectorInternalPseudoSpatialNavigationFocus = 1065,
    kSameOriginTextScript = 1066,
    kSameOriginApplicationScript = 1067,
    kSameOriginOtherScript = 1068,
    kCrossOriginTextScript = 1069,
    kCrossOriginApplicationScript = 1070,
    kCrossOriginOtherScript = 1071,
    kSVG1DOMSVGTests = 1072,
    kDisableRemotePlaybackAttribute = 1074,
    kV8SloppyMode = 1075,
    kV8StrictMode = 1076,
    kV8StrongMode = 1077,
    kAudioNodeConnectToAudioNode = 1078,
    kAudioNodeConnectToAudioParam = 1079,
    kAudioNodeDisconnectFromAudioNode = 1080,
    kAudioNodeDisconnectFromAudioParam = 1081,
    kV8CSSFontFaceRule_Style_AttributeGetter = 1082,
    kSelectionCollapseNull = 1083,
    kSelectionSetBaseAndExtentNull = 1084,
    kV8SVGSVGElement_CreateSVGNumber_Method = 1085,
    kV8SVGSVGElement_CreateSVGLength_Method = 1086,
    kV8SVGSVGElement_CreateSVGAngle_Method = 1087,
    kV8SVGSVGElement_CreateSVGPoint_Method = 1088,
    kV8SVGSVGElement_CreateSVGMatrix_Method = 1089,
    kV8SVGSVGElement_CreateSVGRect_Method = 1090,
    kV8SVGSVGElement_CreateSVGTransform_Method = 1091,
    kV8SVGSVGElement_CreateSVGTransformFromMatrix_Method = 1092,
    kFormNameAccessForNonDescendantImageElement = 1093,
    kV8RegExpPrototypeStickyGetter = 1096,
    kV8RegExpPrototypeToString = 1097,
    kV8InputDeviceCapabilities_FiresTouchEvents_AttributeGetter = 1098,
    kDataElement = 1099,
    kTimeElement = 1100,
    kSVG1DOMUriReference = 1101,
    kSVG1DOMZoomAndPan = 1102,
    kV8SVGGraphicsElement_Transform_AttributeGetter = 1103,
    kMenuItemElement = 1104,
    kMenuItemCloseTag = 1105,
    kSVG1DOMMarkerElement = 1106,
    kSVG1DOMUseElement = 1107,
    kSVG1DOMMaskElement = 1108,
    kV8SVGAElement_Target_AttributeGetter = 1109,
    kV8SVGClipPathElement_ClipPathUnits_AttributeGetter = 1110,
    kSVG1DOMFitToViewBox = 1111,
    kSVG1DOMSVGElement = 1114,
    kSVG1DOMImageElement = 1115,
    kSVG1DOMForeignObjectElement = 1116,
    kAudioContextCreateIIRFilter = 1117,
    // The above items are available in M49 branch

    kCSSSelectorPseudoSlotted = 1118,
    kMediaDevicesEnumerateDevices = 1119,
    kNonSecureSharedWorkerAccessedFromSecureContext = 1120,
    kSecureSharedWorkerAccessedFromNonSecureContext = 1121,
    kEventComposedPath = 1123,
    kLinkHeaderPreload = 1124,
    kMouseWheelEvent = 1125,
    kWheelEvent = 1126,
    kMouseWheelAndWheelEvent = 1127,
    kBodyScrollsInAdditionToViewport = 1128,
    kDocumentDesignModeEnabeld = 1129,
    kContentEditableTrue = 1130,
    kContentEditableTrueOnHTML = 1131,
    kContentEditablePlainTextOnly = 1132,
    kV8RegExpPrototypeUnicodeGetter = 1133,
    kV8IntlV8Parse = 1134,
    kV8IntlPattern = 1135,
    kV8IntlResolved = 1136,
    kV8PromiseChain = 1137,
    kV8PromiseAccept = 1138,
    kV8PromiseDefer = 1139,
    kEventComposed = 1140,
    kGeolocationInsecureOriginIframe = 1141,
    kGeolocationSecureOriginIframe = 1142,
    kRequestMIDIAccessIframe = 1143,
    kGetUserMediaInsecureOriginIframe = 1144,
    kGetUserMediaSecureOriginIframe = 1145,
    kElementRequestPointerLockIframe = 1146,
    kNotificationAPIInsecureOriginIframe = 1147,
    kNotificationAPISecureOriginIframe = 1148,
    kWebSocket = 1149,
    kMediaStreamConstraintsNameValue = 1150,
    kMediaStreamConstraintsFromDictionary = 1151,
    kMediaStreamConstraintsConformant = 1152,
    kCSSSelectorIndirectAdjacent = 1153,
    kCreateImageBitmap = 1156,
    kPresentationConnectionConnectEventListener = 1157,
    kPresentationConnectionCloseEventListener = 1158,
    kPresentationConnectionTerminateEventListener = 1159,
    kDocumentCreateEventAnimationEvent = 1162,
    kDocumentCreateEventBeforeUnloadEvent = 1166,
    kDocumentCreateEventCompositionEvent = 1168,
    kDocumentCreateEventDragEvent = 1169,
    kDocumentCreateEventErrorEvent = 1170,
    kDocumentCreateEventFocusEvent = 1171,
    kDocumentCreateEventHashChangeEvent = 1172,
    kDocumentCreateEventMutationEvent = 1173,
    kDocumentCreateEventPageTransitionEvent = 1174,
    kDocumentCreateEventPopStateEvent = 1176,
    kDocumentCreateEventTextEvent = 1182,
    kDocumentCreateEventTransitionEvent = 1183,
    kDocumentCreateEventWheelEvent = 1184,
    kDocumentCreateEventTrackEvent = 1186,
    kDocumentCreateEventMutationEvents = 1188,
    kDocumentCreateEventSVGEvents = 1190,
    kDocumentCreateEventDeviceMotionEvent = 1195,
    kDocumentCreateEventDeviceOrientationEvent = 1196,
    kDocumentCreateEventIDBVersionChangeEvent = 1201,
    kDocumentCreateEventStorageEvent = 1221,
    kDocumentCreateEventWebGLContextEvent = 1224,
    kDocumentCreateEventCloseEvent = 1227,
    kDocumentCreateEventKeyboardEvents = 1228,
    kHTMLMediaElement = 1229,
    kHTMLMediaElementInDocument = 1230,
    kHTMLMediaElementControlsAttribute = 1231,
    kV8Animation_Oncancel_AttributeGetter = 1233,
    kV8Animation_Oncancel_AttributeSetter = 1234,
    kV8HTMLCommentInExternalScript = 1235,
    kV8HTMLComment = 1236,
    kV8SloppyModeBlockScopedFunctionRedefinition = 1237,
    kV8ForInInitializer = 1238,
    kV8Animation_Id_AttributeGetter = 1239,
    kV8Animation_Id_AttributeSetter = 1240,
    kApplicationCacheManifestSelectInsecureOrigin = 1245,
    kApplicationCacheManifestSelectSecureOrigin = 1246,
    kApplicationCacheAPIInsecureOrigin = 1247,
    kApplicationCacheAPISecureOrigin = 1248,
    // The above items are available in M50 branch

    kCSSAtRuleApply = 1249,
    kCSSSelectorPseudoAny = 1250,
    kDocumentAllItemNoArguments = 1252,
    kDocumentAllItemNamed = 1253,
    kDocumentAllItemIndexed = 1254,
    kDocumentAllItemIndexedWithNonNumber = 1255,
    kDocumentAllLegacyCallNoArguments = 1256,
    kDocumentAllLegacyCallNamed = 1257,
    kDocumentAllLegacyCallIndexed = 1258,
    kDocumentAllLegacyCallIndexedWithNonNumber = 1259,
    kDocumentAllLegacyCallTwoArguments = 1260,
    kHTMLLabelElementControlForNonFormAssociatedElement = 1263,
    kHTMLMediaElementLoadNetworkEmptyNotPaused = 1265,
    kV8Window_WebkitSpeechGrammar_ConstructorGetter = 1267,
    kV8Window_WebkitSpeechGrammarList_ConstructorGetter = 1268,
    kV8Window_WebkitSpeechRecognition_ConstructorGetter = 1269,
    kV8Window_WebkitSpeechRecognitionError_ConstructorGetter = 1270,
    kV8Window_WebkitSpeechRecognitionEvent_ConstructorGetter = 1271,
    kV8Window_SpeechSynthesis_AttributeGetter = 1272,
    kV8IDBFactory_WebkitGetDatabaseNames_Method = 1273,
    kImageDocument = 1274,
    kScriptPassesCSPDynamic = 1275,
    kCSPWithStrictDynamic = 1277,
    kScrollAnchored = 1278,
    kAddEventListenerFourArguments = 1279,
    kRemoveEventListenerFourArguments = 1280,
    kSVGCalcModeDiscrete = 1287,
    kSVGCalcModeLinear = 1288,
    kSVGCalcModePaced = 1289,
    kSVGCalcModeSpline = 1290,
    kFormSubmissionStarted = 1291,
    kFormValidationStarted = 1292,
    kFormValidationAbortedSubmission = 1293,
    kFormValidationShowedMessage = 1294,
    kWebAnimationsEasingAsFunctionLinear = 1295,
    kWebAnimationsEasingAsFunctionOther = 1296,
    // The above items are available in M51 branch

    kV8Document_Images_AttributeGetter = 1297,
    kV8Document_Embeds_AttributeGetter = 1298,
    kV8Document_Plugins_AttributeGetter = 1299,
    kV8Document_Links_AttributeGetter = 1300,
    kV8Document_Forms_AttributeGetter = 1301,
    kV8Document_Scripts_AttributeGetter = 1302,
    kV8Document_Anchors_AttributeGetter = 1303,
    kV8Document_Applets_AttributeGetter = 1304,
    kXMLHttpRequestCrossOriginWithCredentials = 1305,
    kMediaStreamTrackRemote = 1306,
    kV8Node_IsConnected_AttributeGetter = 1307,
    kShadowRootDelegatesFocus = 1308,
    kMixedShadowRootV0AndV1 = 1309,
    kImageDocumentInFrame = 1310,
    kMediaDocument = 1311,
    kMediaDocumentInFrame = 1312,
    kPluginDocument = 1313,
    kPluginDocumentInFrame = 1314,
    kSinkDocument = 1315,
    kSinkDocumentInFrame = 1316,
    kTextDocument = 1317,
    kTextDocumentInFrame = 1318,
    kViewSourceDocument = 1319,
    kFileAPINativeLineEndings = 1320,
    kPointerEventAttributeCount = 1321,
    kCompositedReplication = 1322,
    kV8DataTransferItem_WebkitGetAsEntry_Method = 1325,
    kV8HTMLInputElement_WebkitEntries_AttributeGetter = 1326,
    kEntry_Filesystem_AttributeGetter_IsolatedFileSystem = 1327,
    kEntry_GetMetadata_Method_IsolatedFileSystem = 1328,
    kEntry_MoveTo_Method_IsolatedFileSystem = 1329,
    kEntry_CopyTo_Method_IsolatedFileSystem = 1330,
    kEntry_Remove_Method_IsolatedFileSystem = 1331,
    kEntry_GetParent_Method_IsolatedFileSystem = 1332,
    kEntry_ToURL_Method_IsolatedFileSystem = 1333,
    kDuring_Microtask_Alert = 1334,
    kDuring_Microtask_Confirm = 1335,
    kDuring_Microtask_Print = 1336,
    kDuring_Microtask_Prompt = 1337,
    kDuring_Microtask_SyncXHR = 1338,
    kCredentialManagerGetReturnedCredential = 1342,
    kGeolocationInsecureOriginDeprecatedNotRemoved = 1343,
    kGeolocationInsecureOriginIframeDeprecatedNotRemoved = 1344,
    kProgressElementWithNoneAppearance = 1345,
    kProgressElementWithProgressBarAppearance = 1346,
    kPointerEventAddListenerCount = 1347,
    kCSSValueAppearanceNone = 1351,
    kCSSValueAppearanceNotNone = 1352,
    kCSSValueAppearanceOthers = 1353,
    kCSSValueAppearanceButton = 1354,
    kCSSValueAppearanceCaret = 1355,
    kCSSValueAppearanceCheckbox = 1356,
    kCSSValueAppearanceMenulist = 1357,
    kCSSValueAppearanceMenulistButton = 1358,
    kCSSValueAppearanceListbox = 1359,
    kCSSValueAppearanceRadio = 1360,
    kCSSValueAppearanceSearchField = 1361,
    kCSSValueAppearanceTextField = 1362,
    kAudioContextCreatePannerAutomated = 1363,
    kPannerNodeSetPosition = 1364,
    kPannerNodeSetOrientation = 1365,
    kAudioListenerSetPosition = 1366,
    kAudioListenerSetOrientation = 1367,
    kIntersectionObserver_Constructor = 1368,
    kDurableStoragePersist = 1369,
    kDurableStoragePersisted = 1370,
    kDurableStorageEstimate = 1371,
    kCSSDeepCombinatorAndShadow = 1375,
    kOpacityWithPreserve3DQuirk = 1376,
    kCSSSelectorPseudoReadOnly = 1377,
    kCSSSelectorPseudoReadWrite = 1378,
    // The above items are available in M52 branch

    kCSSSelectorPseudoDefined = 1383,
    kRTCPeerConnectionAddIceCandidatePromise = 1384,
    kRTCPeerConnectionAddIceCandidateLegacy = 1385,
    kRTCIceCandidateDefaultSdpMLineIndex = 1386,
    kMediaStreamConstraintsOldAndNew = 1389,
    kV8ArrayProtectorDirtied = 1390,
    kV8ArraySpeciesModified = 1391,
    kV8ArrayPrototypeConstructorModified = 1392,
    kV8ArrayInstanceProtoModified = 1393,
    kV8ArrayInstanceConstructorModified = 1394,
    kV8LegacyFunctionDeclaration = 1395,
    kV8RegExpPrototypeSourceGetter = 1396,
    kV8RegExpPrototypeOldFlagGetter = 1397,
    kV8DecimalWithLeadingZeroInStrictMode = 1398,
    kGetUserMediaPrefixed = 1400,
    kGetUserMediaLegacy = 1401,
    kGetUserMediaPromise = 1402,
    kCSSFilterFunctionNoArguments = 1403,
    kV8LegacyDateParser = 1404,
    kOpenSearchInsecureOriginInsecureTarget = 1405,
    kOpenSearchInsecureOriginSecureTarget = 1406,
    kOpenSearchSecureOriginInsecureTarget = 1407,
    kOpenSearchSecureOriginSecureTarget = 1408,
    kRegisterProtocolHandlerSecureOrigin = 1409,
    kRegisterProtocolHandlerInsecureOrigin = 1410,
    kCrossOriginWindowAlert = 1411,
    kCrossOriginWindowConfirm = 1412,
    kCrossOriginWindowPrompt = 1413,
    kCrossOriginWindowPrint = 1414,
    kMediaStreamOnActive = 1415,
    kMediaStreamOnInactive = 1416,
    kAddEventListenerPassiveTrue = 1417,
    kAddEventListenerPassiveFalse = 1418,
    kCSPReferrerDirective = 1419,
    kDocumentOpen = 1420,
    kElementRequestPointerLockInShadow = 1421,
    kShadowRootPointerLockElement = 1422,
    kDocumentPointerLockElementInV0Shadow = 1423,
    kTextAreaMaxLength = 1424,
    kTextAreaMinLength = 1425,
    kTopNavigationFromSubFrame = 1426,
    kPrefixedElementRequestFullscreenInShadow = 1427,
    kMediaSourceAbortRemove = 1428,
    kMediaSourceDurationTruncatingBuffered = 1429,
    kAudioContextCrossOriginIframe = 1430,
    // The above items are available in M53 branch

    kPointerEventSetCapture = 1431,
    kPointerEventDispatch = 1432,
    kMIDIMessageEventReceivedTime = 1433,
    kSummaryElementWithDisplayBlockAuthorRule = 1434,
    kV8MediaStream_Active_AttributeGetter = 1435,
    kBeforeInstallPromptEvent = 1436,
    kBeforeInstallPromptEventUserChoice = 1437,
    kBeforeInstallPromptEventPreventDefault = 1438,
    kBeforeInstallPromptEventPrompt = 1439,
    kExecCommandAltersHTMLStructure = 1440,
    kSecureContextCheckPassed = 1441,
    kSecureContextCheckFailed = 1442,
    kSecureContextCheckForSandboxedOriginPassed = 1443,
    kSecureContextCheckForSandboxedOriginFailed = 1444,
    kV8DefineGetterOrSetterWouldThrow = 1445,
    kV8FunctionConstructorReturnedUndefined = 1446,
    kV8BroadcastChannel_Constructor = 1447,
    kV8BroadcastChannel_PostMessage_Method = 1448,
    kV8BroadcastChannel_Close_Method = 1449,
    kTouchStartFired = 1450,
    kMouseDownFired = 1451,
    kPointerDownFired = 1452,
    kPointerDownFiredForTouch = 1453,
    kPointerEventDispatchPointerDown = 1454,
    kSVGSMILBeginOrEndEventValue = 1455,
    kSVGSMILBeginOrEndSyncbaseValue = 1456,
    kSVGSMILElementInsertedAfterLoad = 1457,
    kV8VisualViewport_ScrollLeft_AttributeGetter = 1458,
    kV8VisualViewport_ScrollTop_AttributeGetter = 1459,
    kV8VisualViewport_PageX_AttributeGetter = 1460,
    kV8VisualViewport_PageY_AttributeGetter = 1461,
    kV8VisualViewport_ClientWidth_AttributeGetter = 1462,
    kV8VisualViewport_ClientHeight_AttributeGetter = 1463,
    kV8VisualViewport_Scale_AttributeGetter = 1464,
    kVisualViewportScrollFired = 1465,
    kVisualViewportResizeFired = 1466,
    kNodeGetRootNode = 1467,
    kSlotChangeEventAddListener = 1468,
    kCSSValueAppearanceButtonRendered = 1469,
    kCSSValueAppearanceButtonForAnchor = 1470,
    kCSSValueAppearanceButtonForButton = 1471,
    kCSSValueAppearanceButtonForOtherButtons = 1472,
    kCSSValueAppearanceTextFieldRendered = 1473,
    kCSSValueAppearanceTextFieldForSearch = 1474,
    kCSSValueAppearanceTextFieldForTextField = 1475,
    kRTCPeerConnectionGetStats = 1476,
    kSVGSMILAnimationAppliedEffect = 1477,
    kPerformanceResourceTimingSizes = 1478,
    kEventSourceDocument = 1479,
    kEventSourceWorker = 1480,
    kSingleOriginInTimingAllowOrigin = 1481,
    kMultipleOriginsInTimingAllowOrigin = 1482,
    kStarInTimingAllowOrigin = 1483,
    kSVGSMILAdditiveAnimation = 1484,
    kSendBeaconWithNonSimpleContentType = 1485,
    kChromeLoadTimesRequestTime = 1486,
    kChromeLoadTimesStartLoadTime = 1487,
    kChromeLoadTimesCommitLoadTime = 1488,
    kChromeLoadTimesFinishDocumentLoadTime = 1489,
    kChromeLoadTimesFinishLoadTime = 1490,
    kChromeLoadTimesFirstPaintTime = 1491,
    kChromeLoadTimesFirstPaintAfterLoadTime = 1492,
    kChromeLoadTimesNavigationType = 1493,
    kChromeLoadTimesWasFetchedViaSpdy = 1494,
    kChromeLoadTimesWasNpnNegotiated = 1495,
    kChromeLoadTimesNpnNegotiatedProtocol = 1496,
    kChromeLoadTimesWasAlternateProtocolAvailable = 1497,
    kChromeLoadTimesConnectionInfo = 1498,
    kChromeLoadTimesUnknown = 1499,
    kSVGViewElement = 1500,
    kWebShareShare = 1501,
    kAuxclickAddListenerCount = 1502,
    kHTMLCanvasElement = 1503,
    kSVGSMILAnimationElementTiming = 1504,
    kSVGSMILBeginEndAnimationElement = 1505,
    kSVGSMILPausing = 1506,
    kSVGSMILCurrentTime = 1507,
    kHTMLBodyElementOnSelectionChangeAttribute = 1508,
    kForeignFetchInterception = 1509,
    kUsbGetDevices = 1519,
    kUsbRequestDevice = 1520,
    kUsbDeviceOpen = 1521,
    kUsbDeviceClose = 1522,
    kUsbDeviceSelectConfiguration = 1523,
    kUsbDeviceClaimInterface = 1524,
    kUsbDeviceReleaseInterface = 1525,
    kUsbDeviceSelectAlternateInterface = 1526,
    kUsbDeviceControlTransferIn = 1527,
    kUsbDeviceControlTransferOut = 1528,
    kUsbDeviceClearHalt = 1529,
    kUsbDeviceTransferIn = 1530,
    kUsbDeviceTransferOut = 1531,
    kUsbDeviceIsochronousTransferIn = 1532,
    kUsbDeviceIsochronousTransferOut = 1533,
    kUsbDeviceReset = 1534,
    // The above items are available in M54 branch

    kPointerEnterLeaveFired = 1535,
    kPointerOverOutFired = 1536,
    kDraggableAttribute = 1539,
    kCleanScriptElementWithNonce = 1540,
    kPotentiallyInjectedScriptElementWithNonce = 1541,
    kPendingStylesheetAddedAfterBodyStarted = 1542,
    kUntrustedMouseDownEventDispatchedToSelect = 1543,
    kBlockedSniffingAudioToScript = 1544,
    kBlockedSniffingVideoToScript = 1545,
    kBlockedSniffingCSVToScript = 1546,
    kMetaSetCookie = 1547,
    kMetaRefresh = 1548,
    kMetaSetCookieWhenCSPBlocksInlineScript = 1549,
    kMetaRefreshWhenCSPBlocksInlineScript = 1550,
    kMiddleClickAutoscrollStart = 1551,
    kRTCPeerConnectionCreateOfferOptionsOfferToReceive = 1553,
    kDragAndDropScrollStart = 1554,
    kPresentationConnectionListConnectionAvailableEventListener = 1555,
    kWebAudioAutoplayCrossOriginIframe = 1556,
    kVRGetDisplays = 1558,
    kXSSAuditorBlockedScript = 1581,
    kXSSAuditorBlockedEntirePage = 1582,
    kXSSAuditorDisabled = 1583,
    kXSSAuditorEnabledFilter = 1584,
    kXSSAuditorEnabledBlock = 1585,
    kXSSAuditorInvalid = 1586,
    kTextInputEventOnInput = 1589,
    kTextInputEventOnTextArea = 1590,
    kTextInputEventOnContentEditable = 1591,
    kTextInputEventOnNotNode = 1592,
    kWebkitBeforeTextInsertedOnInput = 1593,
    kWebkitBeforeTextInsertedOnTextArea = 1594,
    kWebkitBeforeTextInsertedOnContentEditable = 1595,
    kWebkitBeforeTextInsertedOnNotNode = 1596,
    kWebkitEditableContentChangedOnInput = 1597,
    kWebkitEditableContentChangedOnTextArea = 1598,
    kWebkitEditableContentChangedOnContentEditable = 1599,
    kWebkitEditableContentChangedOnNotNode = 1600,
    kV8NavigatorUserMediaError_ConstraintName_AttributeGetter = 1601,
    kV8HTMLMediaElement_SrcObject_AttributeGetter = 1602,
    kV8HTMLMediaElement_SrcObject_AttributeSetter = 1603,
    kCreateObjectURLBlob = 1604,
    kCreateObjectURLMediaSource = 1605,
    kCreateObjectURLMediaStream = 1606,
    kDocumentCreateTouchWindowNull = 1607,
    kDocumentCreateTouchWindowWrongType = 1608,
    kDocumentCreateTouchTargetNull = 1609,
    kDocumentCreateTouchTargetWrongType = 1610,
    kDocumentCreateTouchMoreThanSevenArguments = 1612,
    kLongTaskObserver = 1615,
    kCSSOffsetInEffect = 1617,
    // The above items are available in M55 branch

    kVRGetDisplaysInsecureOrigin = 1618,
    kVRRequestPresent = 1619,
    kVRRequestPresentInsecureOrigin = 1620,
    kVRDeprecatedFieldOfView = 1621,
    kVideoInCanvas = 1622,
    kHiddenAutoplayedVideoInCanvas = 1623,
    kOffscreenCanvas = 1624,
    kGamepadPose = 1625,
    kGamepadHand = 1626,
    kGamepadDisplayId = 1627,
    kGamepadButtonTouched = 1628,
    kGamepadPoseHasOrientation = 1629,
    kGamepadPoseHasPosition = 1630,
    kGamepadPosePosition = 1631,
    kGamepadPoseLinearVelocity = 1632,
    kGamepadPoseLinearAcceleration = 1633,
    kGamepadPoseOrientation = 1634,
    kGamepadPoseAngularVelocity = 1635,
    kGamepadPoseAngularAcceleration = 1636,
    kV8RTCDataChannel_MaxRetransmitTime_AttributeGetter = 1638,
    kV8RTCDataChannel_MaxRetransmits_AttributeGetter = 1639,
    kV8RTCDataChannel_Reliable_AttributeGetter = 1640,
    kV8RTCPeerConnection_AddStream_Method = 1641,
    kV8RTCPeerConnection_CreateDTMFSender_Method = 1642,
    kV8RTCPeerConnection_GetLocalStreams_Method = 1643,
    kV8RTCPeerConnection_GetRemoteStreams_Method = 1644,
    kV8RTCPeerConnection_GetStreamById_Method = 1645,
    kV8RTCPeerConnection_RemoveStream_Method = 1646,
    kRTCPeerConnectionCreateDataChannelMaxRetransmitTime = 1648,
    kRTCPeerConnectionCreateDataChannelMaxRetransmits = 1649,
    kAudioContextCreateConstantSource = 1650,
    kWebAudioConstantSourceNode = 1651,
    kLoopbackEmbeddedInSecureContext = 1652,
    kLoopbackEmbeddedInNonSecureContext = 1653,
    kBlinkMacSystemFont = 1654,
    kRTCIceServerURL = 1656,
    kRTCIceServerURLs = 1657,
    kOffscreenCanvasTransferToImageBitmap2D = 1658,
    kOffscreenCanvasTransferToImageBitmapWebGL = 1659,
    kOffscreenCanvasCommit2D = 1660,
    kOffscreenCanvasCommitWebGL = 1661,
    kRTCConfigurationIceTransportPolicy = 1662,
    kRTCConfigurationIceTransports = 1664,
    kDocumentFullscreenElementInV0Shadow = 1665,
    kScriptWithCSPBypassingSchemeParserInserted = 1666,
    kScriptWithCSPBypassingSchemeNotParserInserted = 1667,
    kDocumentCreateElement2ndArgStringHandling = 1668,
    kV8MediaRecorder_Start_Method = 1669,
    kWebBluetoothRequestDevice = 1670,
    kUnitlessPerspectiveInPerspectiveProperty = 1671,
    kUnitlessPerspectiveInTransformProperty = 1672,
    kV8RTCSessionDescription_Type_AttributeGetter = 1673,
    kV8RTCSessionDescription_Type_AttributeSetter = 1674,
    kV8RTCSessionDescription_Sdp_AttributeGetter = 1675,
    kV8RTCSessionDescription_Sdp_AttributeSetter = 1676,
    kRTCSessionDescriptionInitNoType = 1677,
    kRTCSessionDescriptionInitNoSdp = 1678,
    kHTMLMediaElementPreloadForcedMetadata = 1679,
    kGenericSensorStart = 1680,
    kGenericSensorStop = 1681,
    kTouchEventPreventedNoTouchAction = 1682,
    kTouchEventPreventedForcedDocumentPassiveNoTouchAction = 1683,
    kV8Event_StopPropagation_Method = 1684,
    kV8Event_StopImmediatePropagation_Method = 1685,
    kImageCaptureConstructor = 1686,
    kV8Document_RootScroller_AttributeGetter = 1687,
    kV8Document_RootScroller_AttributeSetter = 1688,
    kCustomElementRegistryDefine = 1689,
    kLinkHeaderServiceWorker = 1690,
    kCSSShadowPiercingDescendantCombinator = 1691,
    // The above items are available in M56 branch.

    kCSSFlexibleBox = 1692,
    kCSSGridLayout = 1693,
    kFullscreenAllowedByOrientationChange = 1696,
    kServiceWorkerRespondToNavigationRequestWithRedirectedResponse = 1697,
    kV8AudioContext_Constructor = 1698,
    kV8OfflineAudioContext_Constructor = 1699,
    kAppInstalledEventAddListener = 1700,
    kAudioContextGetOutputTimestamp = 1701,
    kV8MediaStreamAudioDestinationNode_Constructor = 1702,
    kV8AnalyserNode_Constructor = 1703,
    kV8AudioBuffer_Constructor = 1704,
    kV8AudioBufferSourceNode_Constructor = 1705,
    kV8AudioProcessingEvent_Constructor = 1706,
    kV8BiquadFilterNode_Constructor = 1707,
    kV8ChannelMergerNode_Constructor = 1708,
    kV8ChannelSplitterNode_Constructor = 1709,
    kV8ConstantSourceNode_Constructor = 1710,
    kV8ConvolverNode_Constructor = 1711,
    kV8DelayNode_Constructor = 1712,
    kV8DynamicsCompressorNode_Constructor = 1713,
    kV8GainNode_Constructor = 1714,
    kV8IIRFilterNode_Constructor = 1715,
    kV8MediaElementAudioSourceNode_Constructor = 1716,
    kV8MediaStreamAudioSourceNode_Constructor = 1717,
    kV8OfflineAudioCompletionEvent_Constructor = 1718,
    kV8OscillatorNode_Constructor = 1719,
    kV8PannerNode_Constructor = 1720,
    kV8PeriodicWave_Constructor = 1721,
    kV8StereoPannerNode_Constructor = 1722,
    kV8WaveShaperNode_Constructor = 1723,
    kV8Headers_GetAll_Method = 1724,
    kNavigatorVibrateEngagementNone = 1725,
    kNavigatorVibrateEngagementMinimal = 1726,
    kNavigatorVibrateEngagementLow = 1727,
    kNavigatorVibrateEngagementMedium = 1728,
    kNavigatorVibrateEngagementHigh = 1729,
    kNavigatorVibrateEngagementMax = 1730,
    kAlertEngagementNone = 1731,
    kAlertEngagementMinimal = 1732,
    kAlertEngagementLow = 1733,
    kAlertEngagementMedium = 1734,
    kAlertEngagementHigh = 1735,
    kAlertEngagementMax = 1736,
    kConfirmEngagementNone = 1737,
    kConfirmEngagementMinimal = 1738,
    kConfirmEngagementLow = 1739,
    kConfirmEngagementMedium = 1740,
    kConfirmEngagementHigh = 1741,
    kConfirmEngagementMax = 1742,
    kPromptEngagementNone = 1743,
    kPromptEngagementMinimal = 1744,
    kPromptEngagementLow = 1745,
    kPromptEngagementMedium = 1746,
    kPromptEngagementHigh = 1747,
    kPromptEngagementMax = 1748,
    kTopNavInSandbox = 1749,
    kTopNavInSandboxWithoutGesture = 1750,
    kTopNavInSandboxWithPerm = 1751,
    kTopNavInSandboxWithPermButNoGesture = 1752,
    kReferrerPolicyHeader = 1753,
    kHTMLAnchorElementReferrerPolicyAttribute = 1754,
    kHTMLIFrameElementReferrerPolicyAttribute = 1755,
    kHTMLImageElementReferrerPolicyAttribute = 1756,
    kHTMLLinkElementReferrerPolicyAttribute = 1757,
    kBaseElement = 1758,
    kBaseWithCrossOriginHref = 1759,
    kBaseWithDataHref = 1760,
    kBaseWithNewlinesInTarget = 1761,
    kBaseWithOpenBracketInTarget = 1762,
    kBaseWouldBeBlockedByDefaultSrc = 1763,
    kV8AssigmentExpressionLHSIsCallInSloppy = 1764,
    kV8AssigmentExpressionLHSIsCallInStrict = 1765,
    kV8PromiseConstructorReturnedUndefined = 1766,
    kFormSubmittedWithUnclosedFormControl = 1767,
    kScrollbarUseVerticalScrollbarButton = 1777,
    kScrollbarUseVerticalScrollbarThumb = 1778,
    kScrollbarUseVerticalScrollbarTrack = 1779,
    kScrollbarUseHorizontalScrollbarButton = 1780,
    kScrollbarUseHorizontalScrollbarThumb = 1781,
    kScrollbarUseHorizontalScrollbarTrack = 1782,
    kHTMLTableCellElementColspan = 1783,
    kHTMLTableCellElementColspanGreaterThan1000 = 1784,
    kHTMLTableCellElementColspanGreaterThan8190 = 1785,
    kSelectionAddRangeIntersect = 1786,
    kPostMessageFromInsecureToSecureToplevel = 1787,
    // The above items are available in M57 branch.

    kV8MediaSession_Metadata_AttributeGetter = 1788,
    kV8MediaSession_Metadata_AttributeSetter = 1789,
    kV8MediaSession_PlaybackState_AttributeGetter = 1790,
    kV8MediaSession_PlaybackState_AttributeSetter = 1791,
    kV8MediaSession_SetActionHandler_Method = 1792,
    kWebNFCPush = 1793,
    kWebNFCCancelPush = 1794,
    kWebNFCWatch = 1795,
    kWebNFCCancelWatch = 1796,
    kAudioParamCancelAndHoldAtTime = 1797,
    kCSSValueUserModifyReadOnly = 1798,
    kCSSValueUserModifyReadWrite = 1799,
    kCSSValueUserModifyReadWritePlaintextOnly = 1800,
    kCSSValueOnDemand = 1802,
    kServiceWorkerNavigationPreload = 1803,
    kFullscreenRequestWithPendingElement = 1804,
    kHTMLIFrameElementAllowfullscreenAttributeSetAfterContentLoad = 1805,
    kPointerEventSetCaptureOutsideDispatch = 1806,
    kNotificationPermissionRequestedInsecureOrigin = 1807,
    kV8DeprecatedStorageInfo_QueryUsageAndQuota_Method = 1808,
    kV8DeprecatedStorageInfo_RequestQuota_Method = 1809,
    kV8DeprecatedStorageQuota_QueryUsageAndQuota_Method = 1810,
    kV8DeprecatedStorageQuota_RequestQuota_Method = 1811,
    kV8FileReaderSync_Constructor = 1812,
    kUncancelableTouchEventPreventDefaulted = 1813,
    kUncancelableTouchEventDueToMainThreadResponsivenessPreventDefaulted = 1814,
    kV8HTMLVideoElement_Poster_AttributeGetter = 1815,
    kV8HTMLVideoElement_Poster_AttributeSetter = 1816,
    kNotificationPermissionRequestedIframe = 1817,
    kPresentationReceiverInsecureOrigin = 1819,
    kPresentationReceiverSecureOrigin = 1820,
    kPresentationRequestInsecureOrigin = 1821,
    kPresentationRequestSecureOrigin = 1822,
    kRtcpMuxPolicyNegotiate = 1823,
    kDOMClobberedVariableAccessed = 1824,
    kHTMLDocumentCreateProcessingInstruction = 1825,
    kFetchResponseConstructionWithStream = 1826,
    kLocationOrigin = 1827,
    kDocumentOrigin = 1828,
    kCanvas2DFilter = 1830,
    kCanvas2DImageSmoothingQuality = 1831,
    kCanvasToBlob = 1832,
    kCanvasToDataURL = 1833,
    kOffscreenCanvasConvertToBlob = 1834,
    kSVGInCanvas2D = 1835,
    kSVGInWebGL = 1836,
    kSelectionFuncionsChangeFocus = 1837,
    kHTMLObjectElementGetter = 1838,
    kHTMLObjectElementSetter = 1839,
    kHTMLEmbedElementGetter = 1840,
    kHTMLEmbedElementSetter = 1841,
    kTransformUsesBoxSizeOnSVG = 1842,
    // The above items are available in M58 branch.

    kScrollByKeyboardArrowKeys = 1843,
    kScrollByKeyboardPageUpDownKeys = 1844,
    kScrollByKeyboardHomeEndKeys = 1845,
    kScrollByKeyboardSpacebarKey = 1846,
    kScrollByTouch = 1847,
    kScrollByWheel = 1848,
    kScheduledActionIgnored = 1849,
    kGetCanvas2DContextAttributes = 1850,
    kV8HTMLInputElement_Capture_AttributeGetter = 1851,
    kV8HTMLInputElement_Capture_AttributeSetter = 1852,
    kHTMLMediaElementControlsListAttribute = 1853,
    kHTMLMediaElementControlsListNoDownload = 1854,
    kHTMLMediaElementControlsListNoFullscreen = 1855,
    kHTMLMediaElementControlsListNoRemotePlayback = 1856,
    kPointerEventClickRetargetCausedByCapture = 1857,
    kVRDisplayDisplayName = 1861,
    kVREyeParametersOffset = 1862,
    kVRPoseLinearVelocity = 1863,
    kVRPoseLinearAcceleration = 1864,
    kVRPoseAngularVelocity = 1865,
    kVRPoseAngularAcceleration = 1866,
    kCSSOverflowPaged = 1867,
    kChildSrcAllowedWorkerThatScriptSrcBlocked = 1868,
    kHTMLTableElementPresentationAttributeBackground = 1869,
    kV8Navigator_GetInstalledRelatedApps_Method = 1870,
    kNamedAccessOnWindow_ChildBrowsingContext = 1871,
    kNamedAccessOnWindow_ChildBrowsingContext_CrossOriginNameMismatch = 1872,
    kV0CustomElementsRegisterHTMLCustomTag = 1873,
    kV0CustomElementsRegisterHTMLTypeExtension = 1874,
    kV0CustomElementsRegisterSVGElement = 1875,
    kV0CustomElementsRegisterEmbedderElement = 1876,
    kV0CustomElementsCreateCustomTagElement = 1877,
    kV0CustomElementsCreateTypeExtensionElement = 1878,
    kV0CustomElementsConstruct = 1879,
    kV8IDBObserver_Observe_Method = 1880,
    kV8IDBObserver_Unobserve_Method = 1881,
    kWebBluetoothRemoteCharacteristicGetDescriptor = 1882,
    kWebBluetoothRemoteCharacteristicGetDescriptors = 1883,
    kWebBluetoothRemoteCharacteristicReadValue = 1884,
    kWebBluetoothRemoteCharacteristicWriteValue = 1885,
    kWebBluetoothRemoteCharacteristicStartNotifications = 1886,
    kWebBluetoothRemoteCharacteristicStopNotifications = 1887,
    kWebBluetoothRemoteDescriptorReadValue = 1888,
    kWebBluetoothRemoteDescriptorWriteValue = 1889,
    kWebBluetoothRemoteServerConnect = 1890,
    kWebBluetoothRemoteServerDisconnect = 1891,
    kWebBluetoothRemoteServerGetPrimaryService = 1892,
    kWebBluetoothRemoteServerGetPrimaryServices = 1893,
    kWebBluetoothRemoteServiceGetCharacteristic = 1894,
    kWebBluetoothRemoteServiceGetCharacteristics = 1895,
    kHTMLContentElement = 1896,
    kHTMLShadowElement = 1897,
    kHTMLSlotElement = 1898,
    kAccelerometerConstructor = 1899,
    kAbsoluteOrientationSensorConstructor = 1900,
    kAmbientLightSensorConstructor = 1901,
    kGenericSensorOnActivate = 1902,
    kGenericSensorOnChange = 1903,
    kGenericSensorOnError = 1904,
    kGenericSensorActivated = 1905,
    kGyroscopeConstructor = 1906,
    kMagnetometerConstructor = 1907,
    kOrientationSensorPopulateMatrix = 1908,
    kWindowOpenWithInvalidURL = 1909,
    kCrossOriginMainFrameNulledNameAccessed = 1910,
    kMenuItemElementIconAttribute = 1911,
    kWebkitCSSMatrixSetMatrixValue = 1912,
    kWebkitCSSMatrixConstructFromString = 1913,
    kCanRequestURLHTTPContainingNewline = 1914,
    kGetGamepads = 1916,
    kV8SVGPathElement_GetPathSegAtLength_Method = 1917,
    kMediaStreamConstraintsAudio = 1918,
    kMediaStreamConstraintsAudioUnconstrained = 1919,
    kMediaStreamConstraintsVideo = 1920,
    kMediaStreamConstraintsVideoUnconstrained = 1921,
    kMediaStreamConstraintsWidth = 1922,
    kMediaStreamConstraintsHeight = 1923,
    kMediaStreamConstraintsAspectRatio = 1924,
    kMediaStreamConstraintsFrameRate = 1925,
    kMediaStreamConstraintsFacingMode = 1926,
    kMediaStreamConstraintsVolume = 1927,
    kMediaStreamConstraintsSampleRate = 1928,
    kMediaStreamConstraintsSampleSize = 1929,
    kMediaStreamConstraintsEchoCancellation = 1930,
    kMediaStreamConstraintsLatency = 1931,
    kMediaStreamConstraintsChannelCount = 1932,
    kMediaStreamConstraintsDeviceIdAudio = 1933,
    kMediaStreamConstraintsDeviceIdVideo = 1934,
    kMediaStreamConstraintsDisableLocalEcho = 1935,
    kMediaStreamConstraintsGroupIdAudio = 1936,
    kMediaStreamConstraintsGroupIdVideo = 1937,
    kMediaStreamConstraintsVideoKind = 1938,
    kMediaStreamConstraintsDepthNear = 1939,
    kMediaStreamConstraintsDepthFar = 1940,
    kMediaStreamConstraintsFocalLengthX = 1941,
    kMediaStreamConstraintsFocalLengthY = 1942,
    kMediaStreamConstraintsMediaStreamSourceAudio = 1943,
    kMediaStreamConstraintsMediaStreamSourceVideo = 1944,
    kMediaStreamConstraintsRenderToAssociatedSink = 1945,
    kMediaStreamConstraintsHotwordEnabled = 1946,
    kMediaStreamConstraintsGoogEchoCancellation = 1947,
    kMediaStreamConstraintsGoogExperimentalEchoCancellation = 1948,
    kMediaStreamConstraintsGoogAutoGainControl = 1949,
    kMediaStreamConstraintsGoogExperimentalAutoGainControl = 1950,
    kMediaStreamConstraintsGoogNoiseSuppression = 1951,
    kMediaStreamConstraintsGoogHighpassFilter = 1952,
    kMediaStreamConstraintsGoogTypingNoiseDetection = 1953,
    kMediaStreamConstraintsGoogExperimentalNoiseSuppression = 1954,
    kMediaStreamConstraintsGoogBeamforming = 1955,
    kMediaStreamConstraintsGoogArrayGeometry = 1956,
    kMediaStreamConstraintsGoogAudioMirroring = 1957,
    kMediaStreamConstraintsGoogDAEchoCancellation = 1958,
    kMediaStreamConstraintsGoogNoiseReduction = 1959,
    kMediaStreamConstraintsGoogPowerLineFrequency = 1960,
    // The above items are available in M59 branch.

    kViewportFixedPositionUnderFilter = 1961,
    kRequestMIDIAccessWithSysExOption = 1962,
    kRequestMIDIAccessIframeWithSysExOption = 1963,
    kGamepadAxes = 1964,
    kGamepadButtons = 1965,
    kVibrateWithoutUserGesture = 1966,
    kDispatchMouseEventOnDisabledFormControl = 1967,
    kElementNameDOMInvalidHTMLParserValid = 1968,
    kElementNameDOMValidHTMLParserInvalid = 1969,
    kGATTServerDisconnectedEvent = 1970,
    kAnchorClickDispatchForNonConnectedNode = 1971,
    kHTMLParseErrorNestedForm = 1972,
    kFontShapingNotDefGlyphObserved = 1973,
    kPostMessageOutgoingWouldBeBlockedByConnectSrc = 1974,
    kPostMessageIncomingWouldBeBlockedByConnectSrc = 1975,
    kPaymentRequestNetworkNameInSupportedMethods = 1976,
    kCrossOriginPropertyAccess = 1977,
    kCrossOriginPropertyAccessFromOpener = 1978,
    kCredentialManagerCreate = 1979,
    kWebDatabaseCreateDropFTS3Table = 1980,
    kFieldEditInSecureContext = 1981,
    kFieldEditInNonSecureContext = 1982,
    kCredentialManagerCredentialRequestOptionsUnmediated = 1983,
    kCredentialManagerGetMediationRequired = 1984,
    kCredentialManagerIdName = 1985,
    kCredentialManagerPasswordName = 1986,
    kCredentialManagerAdditionalData = 1987,
    kCredentialManagerCustomFetch = 1988,
    kNetInfoRtt = 1989,
    kNetInfoDownlink = 1990,
    kShapeDetection_BarcodeDetectorConstructor = 1991,
    kShapeDetection_FaceDetectorConstructor = 1992,
    kShapeDetection_TextDetectorConstructor = 1993,
    kCredentialManagerCredentialRequestOptionsOnlyUnmediated = 1994,
    // TODO(aboxhall): Reuse value 1995 when
    // https://codereview.chromium.org/2088453002 is relanded.
    kPluginInstanceAccessFromIsolatedWorld = 1996,
    kPluginInstanceAccessFromMainWorld = 1997,
    kRequestFullscreenForDialogElement = 1998,
    kRequestFullscreenForDialogElementInTopLayer = 1999,
    kShowModalForElementInFullscreenStack = 2000,

    // Add new features immediately above this line. Don't change assigned
    // numbers of any item, and don't reuse removed slots.
    // Also, run update_use_counter_feature_enum.py in
    // chromium/src/tools/metrics/histograms/ to update the UMA mapping.
    kNumberOfFeatures,  // This enum value must be last.
  };

  // An interface to observe UseCounter changes. Note that this is never
  // notified when the counter is disabled by |m_muteCount| or when |m_context|
  // is kDisabledContext.
  class Observer : public GarbageCollected<Observer> {
   public:
    // Notified when a feature is counted for the first time. This should return
    // true if it no longer needs to observe changes so that the counter can
    // remove a reference to the observer and stop notifications.
    virtual bool OnCountFeature(Feature) = 0;

    DEFINE_INLINE_VIRTUAL_TRACE() {}
  };

  // "count" sets the bit for this feature to 1. Repeated calls are ignored.
  static void Count(const Frame*, Feature);
  static void Count(const Document&, Feature);
  static void Count(ExecutionContext*, Feature);

  void Count(CSSParserMode, CSSPropertyID);
  void Count(Feature);

  static void CountAnimatedCSS(const Document&, CSSPropertyID);
  void CountAnimatedCSS(CSSPropertyID);

  // Count only features if they're being used in an iframe which does not
  // have script access into the top level document.
  static void CountCrossOriginIframe(const Document&, Feature);

  // Return whether the Feature was previously counted for this document.
  // NOTE: only for use in testing.
  static bool IsCounted(Document&, Feature);
  // Return whether the CSSPropertyID was previously counted for this document.
  // NOTE: only for use in testing.
  static bool IsCounted(Document&, const String&);
  bool IsCounted(CSSPropertyID unresolved_property);

  // Return whether the CSSPropertyID was previously counted for this document.
  // NOTE: only for use in testing.
  static bool IsCountedAnimatedCSS(Document&, const String&);
  bool IsCountedAnimatedCSS(CSSPropertyID unresolved_property);

  // Retains a reference to the observer to notify of UseCounter changes.
  void AddObserver(Observer*);

  // Invoked when a new document is loaded into the main frame of the page.
  void DidCommitLoad(KURL);

  static int MapCSSPropertyIdToCSSSampleIdForHistogram(CSSPropertyID);

  // When muted, all calls to "count" functions are ignoed.  May be nested.
  void MuteForInspector();
  void UnmuteForInspector();

  void RecordMeasurement(Feature);

  // Return whether the feature has been seen since the last page load
  // (except when muted).  Does include features seen in documents which have
  // reporting disabled.
  bool HasRecordedMeasurement(Feature) const;

  DECLARE_TRACE();

 private:
  // Notifies that a feature is newly counted to |m_observers|. This shouldn't
  // be called when the counter is disabled by |m_muteCount| or when |m_context|
  // if kDisabledContext.
  void NotifyFeatureCounted(Feature);

  EnumerationHistogram& FeaturesHistogram() const;
  EnumerationHistogram& CssHistogram() const;
  EnumerationHistogram& AnimatedCSSHistogram() const;

  // If non-zero, ignore all 'count' calls completely.
  unsigned mute_count_;

  // The scope represented by this UseCounter instance, which must be fixed for
  // the duration of a page but can change when a new page is loaded.
  Context context_;

  // Track what features/properties have been reported to the (non-legacy)
  // histograms.
  BitVector features_recorded_;
  BitVector css_recorded_;
  BitVector animated_css_recorded_;

  HeapHashSet<Member<Observer>> observers_;

  // Encapsulates the work to preserve the old "FeatureObserver" histogram with
  // original semantics
  // TODO(rbyers): remove this - http://crbug.com/676837
  class CORE_EXPORT LegacyCounter {
   public:
    LegacyCounter();
    ~LegacyCounter();
    void CountFeature(Feature);
    void CountCSS(CSSPropertyID);
    void UpdateMeasurements();

   private:
    // Tracks what features/properties need to be reported to the legacy
    // histograms.
    BitVector feature_bits_;
    BitVector css_bits_;
  } legacy_counter_;
};

}  // namespace blink

#endif  // UseCounter_h