webdx_feature.mojom

// Copyright 2024 The Chromium Authors

// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

module blink.mojom;

// ============ Definition for WebDXFeature used for UseCounter ===========
//
// Do not change assigned numbers of existing items: add new features
// to the end of the list.
//
// If you want to mark an item as no-longer-used, simply rename it, prefixing
// "kOBSOLETE_" before the existing name.
// E.g. kFrobulate becomes kOBSOLETE_Frobulate.
//
// A WebDXFeature counter represents actual usage of a high level feature (as
// defined in https://github.com/web-platform-dx/web-features). A WebDXFeature
// can be a JS API, an HTML element, CSS, etc. Generally, we want these counters
// to count usage of a feature by a web developer on a page. I.e. aim to count
// along the following principles:
//
//   * JS invocable API: Call on invocation of central entry points
//     (i.e. constructor, main API method implementations, or other central
//     code paths not likely to be triggered by feature detection or
//     fingerprinting on a web page), or triggered by internal usage in the
//     renderer.
//
//   * HTML: Count when an element is observed, either by being parsed or
//     constructed by script.
//
//   * CSS: Count when a feature is actually used by the page when reasonable,
//     not just present in a loaded CSS file.
//
// The names of features in this enum should map to the identifiers (i.e. .yml
// file names) used by the WebDX community group at the W3C
// (https://github.com/web-platform-dx/web-features/tree/main/features).
// Those identifiers are all lower case alphanumeric identifiers, with dashes
// (-) as word separators. To translate those identifier names to enum names
// here, start with a lower case 'k', then camelcase the name and remove the
// dashes. I.e. "view-transitions" becomes kViewTransitions. More discussion
// about WebDX feature identifier naming can be found at
// https://github.com/web-platform-dx/web-features/tree/main/docs#identifiers
//
// In the event that you're adding a use counter for a feature that is yet to be
// defined by the WebDX community group, file an issue at
// https://github.com/web-platform-dx/web-features/issues/new?assignees=&labels=feature+definition&projects=&template=new-feature.yml,
// pick a name that you feel is likely to become the name that is used as the
// identifier once agreed upon by the WebDX community group, and prefix the name
// with DRAFT_. I.e. if the likely identifier name is sprocket, name your use
// counter kDRAFT_Sprocket. Once the community group has agreed on the
// identifier name, remove DRAFT_ from the use counter name here, and update the
// name itself if necessary.
//
// LINT.IfChange(WebDXFeature)

enum WebDXFeature {
  kPageVisits = 0,
  kCompressionStreams = 1,
  kViewTransitions = 2,
  kPopover = 3,
  kSubgrid = 4,
  kCascadeLayers = 5,
  kAccentColor = 6,
  kAnimationComposition = 7,
  kAppearance = 8,
  kAspectRatio = 9,
  kAvif = 10,
  kBackdropFilter = 11,
  kBlockingRender = 12,
  kBorderImage = 13,
  kBroadcastChannel = 14,
  kCanvasContextLost = 15,
  kColorScheme = 16,
  kComputePressure = 17,
  kConstructedStylesheets = 18,
  kContainerQueries = 19,
  kContainerStyleQueries = 20,
  kContainIntrinsicSize = 21,
  kCounterStyle = 22,
  kCssModules = 23,
  kDeclarativeShadowDom = 24,
  kDialog = 25,
  kDocumentPictureInPicture = 26,
  kFlexboxGap = 27,
  kFlexbox = 28,
  kFocusVisible = 29,
  kFontOpticalSizing = 30,
  kFontPaletteAnimation = 31,
  kFontPalette = 32,
  kFontSynthesisSmallCaps = 33,
  kFontSynthesisStyle = 34,
  kFontSynthesisWeight = 35,
  kFontSynthesis = 36,
  kFontVariantAlternates = 37,
  kGrid = 38,
  kHas = 39,
  kHyphens = 40,
  kIdleDetection = 41,
  kImportMaps = 42,
  kIndividualTransforms = 43,
  kIntersectionObserverV2 = 44,
  kIntersectionObserver = 45,
  kIs = 46,
  kJsModules = 47,
  kMediaSession = 48,
  kOffscreenCanvas = 49,
  kOriginPrivateFileSystem = 50,
  kPictureInPicture = 51,
  kPointerLock = 52,
  kRelativeColor = 53,
  kScope = 54,
  kScrollbarColor = 55,
  kScrollbarGutter = 56,
  kScrollbarWidth = 57,
  kScrollend = 58,
  kScrollSnap = 59,
  kScrollToTextFragment = 60,
  kShowPickerInput = 61,
  kSlot = 62,
  kSpeechRecognition = 63,
  kSpeechSynthesis = 64,
  kStorageAccess = 65,
  kStorageBuckets = 66,
  kTargetText = 67,
  kTemplate = 68,
  kTextIndent = 69,
  kTextSpacingTrim = 70,
  kTextWrapBalance = 71,
  kTextWrapPretty = 72,
  kTransitionBehavior = 73,
  kTrustedTypes = 74,
  kUserPseudos = 75,
  kWebcodecs = 76,
  kWebhid = 77,
  kWebLocks = 78,
  kWebp = 79,
  kWebtransport = 80,
  kWebusb = 81,
  kWebvtt = 82,
  kWhere = 83,
  kDatalist = 84,
  kDirPseudo = 85,
  kHiddenUntilFound = 86,
  kWillChange = 87,
  kAbortsignalAny = 88,
  kNavigation = 89,
  kMathml = 90,
  kCanvasCreateconicgradient = 91,
  kCanvasReset = 92,
  kCanvasRoundrect = 93,
  kCanvasTextBaselines = 94,
  kColorMix = 95,
  kAriaAttributeReflection = 96,
  kAnchorPositioning = 97,
  kImageSet = 98,
  kStructuredClone = 99,
  kSlotAssign = 100,
  kMasks = 101,
  kDeviceOrientationEvents = 102,
  kDRAFT_Gamepad = 103,
  kScreenWakeLock = 104,
  kWebBluetooth = 105,
  kWebNfc = 106,
  kDRAFT_Serial = 107,
  kJsModulesServiceWorkers = 108,
  kJsModulesSharedWorkers = 109,
  kJsModulesWorkers = 110,
  kTwoValueDisplay = 111,
  kOverflowShorthand = 112,
  kFieldSizing = 113,
  kDetailsName = 114,
  kElementCheckVisibility = 115,
  kKeyboardMap = 116,
  kHiddenUntilFoundAttribute = 117,
  kScheduler = 118,
  kKeyboardLock = 119,
  kSearch = 120,
  kAsyncClipboard = 121,
  kParseHtmlUnsafe = 122,
  kClipboardUnsanitizedFormats = 123,
  kAborting = 124,
  kEditContext = 125,
  kPaintOrder = 126,
  kShowPickerSelect = 127,
  kInert = 128,

  // 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.
};

// LINT.ThenChange(//tools/metrics/histograms/enums.xml:WebDXFeatureObserver)