Add Ad Click Attribution as an internal/experimental feature
[WebKit-https.git] / Source / WebCore / page / Settings.yaml
1 # FIXME: Add support for global settings.
2 # FIXME: Add support for custom getters/setters.
3
4 defaultTextEncodingName:
5   type: String
6 ftpDirectoryTemplatePath:
7   type: String
8 localStorageDatabasePath:
9   type: String
10 editableLinkBehavior:
11   type: EditableLinkBehavior
12   initial: EditableLinkDefaultBehavior
13 textDirectionSubmenuInclusionBehavior:
14   type: TextDirectionSubmenuInclusionBehavior
15   initial: TextDirectionSubmenuAutomaticallyIncluded
16 pdfImageCachingPolicy:
17   type: PDFImageCachingPolicy
18   initial: PDFImageCachingDefault
19 passwordEchoDurationInSeconds:
20   type: double
21   initial: 1
22
23 # Sets the magnification value for validation message timer.  If the
24 # magnification value is N, a validation message disappears automatically after
25 # <message length> * N / 1000 seconds.  If N is equal to or less than 0, a
26 # validation message doesn't disappears automaticaly.
27 validationMessageTimerMagnification:
28   type: int
29   initial: 50
30
31 # Number of pixels below which 2D canvas is rendered in software
32 # even if hardware acceleration is enabled.
33 # Hardware acceleration is useful for large canvases where it can avoid the
34 # pixel bandwidth between the CPU and GPU. But GPU acceleration comes at
35 # a price - extra back-buffer and texture copy. Small canvases are also
36 # widely used for stylized fonts. Anti-aliasing text in hardware at that
37 # scale is generally slower. So below a certain size it is better to
38 # draw canvas in software.
39 minimumAccelerated2dCanvasSize:
40   type: int
41   initial: 257*256
42
43 maximumAccelerated2dCanvasSize:
44   type: unsigned
45   initial: 5120*2880
46
47 layoutFallbackWidth:
48   type: int
49   initial: 980
50 deviceWidth:
51   type: int
52   initial: 0
53 deviceHeight:
54   type: int
55   initial: 0
56
57 # Allow clients concerned with memory consumption to set a quota on session storage
58 # since the memory used won't be released until the Page is destroyed.
59 sessionStorageQuota:
60   type: unsigned
61   initial: StorageMap::noQuota
62
63 minimumFontSize:
64   type: int
65   initial: 0
66   onChange: setNeedsRecalcStyleInAllFrames
67 minimumLogicalFontSize:
68   type: int
69   initial: 0
70   onChange: setNeedsRecalcStyleInAllFrames
71 defaultFontSize:
72   type: int
73   initial: 16
74   onChange: setNeedsRecalcStyleInAllFrames
75 defaultFixedFontSize:
76   type: int
77   initial: 13
78   onChange: setNeedsRecalcStyleInAllFrames
79
80 editingBehaviorType:
81   type: EditingBehaviorType
82   initial: editingBehaviorTypeForPlatform()
83 maximumHTMLParserDOMTreeDepth:
84   type: unsigned
85   initial: defaultMaximumHTMLParserDOMTreeDepth
86
87 # This setting only affects site icon image loading if loadsImagesAutomatically setting is false and this setting is true.
88 # All other permutations still heed loadsImagesAutomatically setting.
89 loadsSiteIconsIgnoringImageLoadingSetting:
90   initial: false
91
92 caretBrowsingEnabled:
93   initial: false
94 preventKeyboardDOMEventDispatch:
95   initial: false
96 localStorageEnabled:
97   initial: false
98 allowUniversalAccessFromFileURLs:
99   initial: true
100 allowFileAccessFromFileURLs:
101   initial: true
102 allowSettingAnyXHRHeaderFromFileURLs:
103   initial: false
104 allowCrossOriginSubresourcesToAskForCredentials:
105   initial: false
106 needsStorageAccessFromFileURLsQuirk:
107   initial: true
108 needsFrameNameFallbackToIdQuirk:
109   initial: false
110 useAnonymousModeWhenFetchingMaskImages:
111   initial: true
112 javaScriptCanOpenWindowsAutomatically:
113   initial: false
114 javaScriptCanAccessClipboard:
115   initial: false
116 shouldPrintBackgrounds:
117   initial: false
118 usesDashboardBackwardCompatibilityMode:
119   initial: false
120   conditional: DASHBOARD_SUPPORT
121 clipboardAccessPolicy:
122   type: ClipboardAccessPolicy
123   initial: ClipboardAccessPolicy::RequiresUserGesture
124
125 textAreasAreResizable:
126   initial: false
127   onChange: setNeedsRecalcStyleInAllFrames
128 authorAndUserStylesEnabled:
129   initial: true
130   onChange: setNeedsRecalcStyleInAllFrames
131 userStyleSheetLocation:
132   type: URL
133   onChange: userStyleSheetLocationChanged
134 acceleratedCompositingEnabled:
135   initial: true
136   onChange: setNeedsRecalcStyleInAllFrames
137 acceleratedCompositedAnimationsEnabled:
138   initial: true
139   onChange: setNeedsRecalcStyleInAllFrames
140 showDebugBorders:
141   initial: false
142   onChange: setNeedsRecalcStyleInAllFrames
143 showRepaintCounter:
144   initial: false
145   onChange: setNeedsRecalcStyleInAllFrames
146 visibleDebugOverlayRegions:
147   type: DebugOverlayRegions
148   initial: 0
149 showTiledScrollingIndicator:
150   initial: false
151 resourceUsageOverlayVisible:
152   initial: false
153   onChange: resourceUsageOverlayVisibleChanged
154   condition: RESOURCE_USAGE
155 disableScreenSizeOverride:
156   initial: false
157
158 # This is a quirk we are pro-actively applying to old applications. It changes keyboard event dispatching,
159 # making keyIdentifier available on keypress events, making charCode available on keydown/keyup events,
160 # and getting keypress dispatched in more cases.
161 needsKeyboardEventDisambiguationQuirks:
162   initial: false
163
164 treatsAnyTextCSSLinkAsStylesheet:
165   initial: false
166 shrinksStandaloneImagesToFit:
167   initial: true
168 pageCacheSupportsPlugins:
169   initial: false
170 showsURLsInToolTips:
171   initial: false
172 showsToolTipOverTruncatedText:
173   initial: false
174 forceFTPDirectoryListings:
175   initial: false
176 developerExtrasEnabled:
177   initial: false
178 scriptMarkupEnabled:
179   initial: true
180 needsSiteSpecificQuirks:
181   initial: false
182 domTimersThrottlingEnabled:
183   initial: true
184 webArchiveDebugModeEnabled:
185   initial: false
186   conditional: WEB_ARCHIVE
187 localFileContentSniffingEnabled:
188   initial: false
189 offlineWebApplicationCacheEnabled:
190   initial: false
191 enforceCSSMIMETypeInNoQuirksMode:
192   initial: true
193 usesEncodingDetector:
194   initial: false
195 canvasUsesAcceleratedDrawing:
196   initial: false
197 acceleratedDrawingEnabled:
198   initial: false
199 displayListDrawingEnabled:
200   initial: false
201 acceleratedFiltersEnabled:
202   initial: false
203 useLegacyTextAlignPositionedElementBehavior:
204   initial: false
205 javaScriptRuntimeFlags:
206   type: JSC::RuntimeFlags
207
208 # FIXME: This should really be disabled by default as it makes platforms that don't support the feature download files
209 # they can't use by. Leaving enabled for now to not change existing behavior.
210 downloadableBinaryFontsEnabled:
211   initial: defaultDownloadableBinaryFontsEnabled()
212
213 xssAuditorEnabled:
214   initial: false
215 acceleratedCompositingForFixedPositionEnabled:
216   initial: defaultAcceleratedCompositingForFixedPositionEnabled
217 rubberBandingForSubScrollableRegionsEnabled:
218   initial: true
219   conditional: RUBBER_BANDING
220
221 experimentalNotificationsEnabled:
222   initial: false
223 webGLEnabled:
224   initial: false
225 webGLErrorsToConsoleEnabled:
226   initial: true
227 unhandledPromiseRejectionToConsoleEnabled:
228   initial: true
229 forceSoftwareWebGLRendering:
230   initial: false
231 forceWebGLUsesLowPower:
232   initial: false
233 accelerated2dCanvasEnabled:
234   initial: false
235 loadDeferringEnabled:
236   initial: true
237 webAudioEnabled:
238   initial: false
239 paginateDuringLayoutEnabled:
240   initial: false
241 fullScreenEnabled:
242   initial: false
243   conditional: FULLSCREEN_API
244 asynchronousSpellCheckingEnabled:
245   initial: false
246
247 # This feature requires an implementation of ValidationMessageClient.
248 interactiveFormValidationEnabled:
249   initial: false
250
251 usePreHTML5ParserQuirks:
252   initial: false
253 hyperlinkAuditingEnabled:
254   initial: false
255 crossOriginCheckInGetMatchedCSSRulesDisabled:
256   initial: false
257 forceCompositingMode:
258   initial: false
259 shouldInjectUserScriptsInInitialEmptyDocument:
260   initial: false
261 fixedElementsLayoutRelativeToFrame:
262   initial: false
263 allowDisplayOfInsecureContent:
264   initial: false
265 allowRunningOfInsecureContent:
266   initial: false
267 requiresUserGestureToLoadVideo:
268   initial: defaultRequiresUserGestureToLoadVideo
269 videoPlaybackRequiresUserGesture:
270   initial: defaultVideoPlaybackRequiresUserGesture
271 audioPlaybackRequiresUserGesture:
272   initial: defaultAudioPlaybackRequiresUserGesture
273 mainContentUserGestureOverrideEnabled:
274   initial: false
275 mediaUserGestureInheritsFromDocument:
276   initial: false
277 allowsInlineMediaPlayback:
278   initial: defaultAllowsInlineMediaPlayback
279 allowsInlineMediaPlaybackAfterFullscreen:
280   initial: true
281 inlineMediaPlaybackRequiresPlaysInlineAttribute:
282   initial: defaultInlineMediaPlaybackRequiresPlaysInlineAttribute
283 allowsPictureInPictureMediaPlayback:
284   initial: defaultAllowsPictureInPictureMediaPlayback
285 mediaControlsScaleWithPageZoom:
286   initial: defaultMediaControlsScaleWithPageZoom
287 invisibleAutoplayNotPermitted:
288   initial: false
289 passwordEchoEnabled:
290   initial: false
291 suppressesIncrementalRendering:
292   initial: false
293 incrementalRenderingSuppressionTimeoutInSeconds:
294   type: double
295   initial: defaultIncrementalRenderingSuppressionTimeoutInSeconds
296 backspaceKeyNavigationEnabled:
297   initial: true
298 shouldDisplaySubtitles:
299   initial: false
300   conditional: VIDEO_TRACK
301 shouldDisplayCaptions:
302   initial: false
303   conditional: VIDEO_TRACK
304 shouldDisplayTextDescriptions:
305   initial: false
306   conditional: VIDEO_TRACK
307 scrollingCoordinatorEnabled:
308   initial: false
309 scrollingTreeIncludesFrames:
310   initial: defaultScrollingTreeIncludesFrames
311 scrollAnimatorEnabled:
312   initial: true
313   conditional: SMOOTH_SCROLLING
314 forceUpdateScrollbarsOnMainThreadForPerformanceTesting:
315   initial: false
316 notificationsEnabled:
317   initial: true
318
319 # Some apps needs isLoadingInAPISense to account for active subresource loaders.
320 needsIsLoadingInAPISenseQuirk:
321   initial: false
322
323 shouldRespectImageOrientation:
324   initial: defaultShouldRespectImageOrientation
325 imageSubsamplingEnabled:
326   initial: defaultImageSubsamplingEnabled
327 wantsBalancedSetDefersLoadingBehavior:
328   initial: false
329 requestAnimationFrameEnabled:
330   initial: true
331
332 HTTPSUpgradeEnabled:
333   initial: false
334
335 thirdPartyIframeRedirectBlockingEnabled:
336   initial: true
337
338 cookieEnabled:
339   initial: true
340 mediaEnabled:
341   initial: defaultMediaEnabled
342 DOMPasteAllowed:
343   initial: false
344
345 # When enabled, window.blur() does not change focus, and
346 # window.focus() only changes focus when invoked from the context that
347 # created the window.
348 windowFocusRestricted:
349   initial: true
350
351 diagnosticLoggingEnabled:
352   initial: false
353
354 delegatesPageScaling:
355   initial: false
356
357 plugInSnapshottingEnabled:
358   initial: false
359
360 snapshotAllPlugIns:
361   initial: false
362
363 autostartOriginPlugInSnapshottingEnabled:
364   initial: true
365
366 primaryPlugInSnapshotDetectionEnabled:
367   initial: true
368
369 maximumPlugInSnapshotAttempts:
370   type: unsigned
371   initial: 20
372
373 frameFlattening:
374   type: FrameFlattening
375   initial: FrameFlattening::Disabled
376   onChange: setNeedsRelayoutAllFrames
377
378 asyncFrameScrollingEnabled:
379   initial: false
380   onChange: setNeedsRelayoutAllFrames
381
382 asyncOverflowScrollingEnabled:
383   initial: false
384   onChange: setNeedsRelayoutAllFrames
385
386 webSecurityEnabled:
387   initial: true
388 spatialNavigationEnabled:
389   initial: false
390
391 autoscrollForDragAndDropEnabled:
392   initial: false
393
394 unifiedTextCheckerEnabled:
395   initial: defaultUnifiedTextCheckerEnabled
396
397 logsPageMessagesToSystemConsoleEnabled:
398   initial: false
399
400 backForwardCacheExpirationInterval:
401   type: double
402   initial: 1800
403
404 # Some apps could have a default video poster if it is not set.
405 defaultVideoPosterURL:
406   type: String
407
408 smartInsertDeleteEnabled:
409   initial: defaultSmartInsertDeleteEnabled
410 selectTrailingWhitespaceEnabled:
411   initial: defaultSelectTrailingWhitespaceEnabled
412 selectionAcrossShadowBoundariesEnabled:
413   initial: true
414
415 useLegacyBackgroundSizeShorthandBehavior:
416   initial: false
417 fixedBackgroundsPaintRelativeToDocument:
418   initial: defaultFixedBackgroundsPaintRelativeToDocument
419
420 textAutosizingEnabled:
421   initial: defaultTextAutosizingEnabled()
422   onChange: setNeedsRecalcStyleInAllFrames
423   conditional: TEXT_AUTOSIZING
424 textAutosizingWindowSizeOverride:
425   type: IntSize
426   onChange: setNeedsRecalcStyleInAllFrames
427   conditional: TEXT_AUTOSIZING
428 minimumZoomFontSize:
429   type: float
430   initial: defaultMinimumZoomFontSize()
431   conditional: TEXT_AUTOSIZING
432
433 subpixelAntialiasedLayerTextEnabled:
434   initial: false
435   onChange: setNeedsRecalcStyleInAllFrames
436 simpleLineLayoutEnabled:
437   initial: true
438   onChange: setNeedsRecalcStyleInAllFrames
439 simpleLineLayoutDebugBordersEnabled:
440   initial: false
441   onChange: setNeedsRecalcStyleInAllFrames
442
443 subpixelCSSOMElementMetricsEnabled:
444   initial: false
445
446 useGiantTiles:
447   initial: false
448
449 mediaSourceEnabled:
450   initial: true
451   conditional: MEDIA_SOURCE
452
453 sourceBufferChangeTypeEnabled:
454   initial: true
455   conditional: MEDIA_SOURCE
456
457 # FIXME: Rename to allowMultiElementImplicitFormSubmission once we upstream the iOS changes to WebView.mm.
458 allowMultiElementImplicitSubmission:
459   initial: false
460
461 allowsAirPlayForMediaPlayback:
462   initial: true
463   conditional: WIRELESS_PLAYBACK_TARGET
464
465 shouldConvertPositionStyleOnCopy:
466   initial: false
467
468 maxParseDuration:
469   type: double
470   initial: -1
471 standalone:
472   initial: false
473 telephoneNumberParsingEnabled:
474   initial: false
475 mediaDataLoadsAutomatically:
476   initial: defaultMediaDataLoadsAutomatically
477 alwaysUseAcceleratedOverflowScroll:
478   initial: false
479 imageControlsEnabled:
480   initial: false
481   conditional: SERVICE_CONTROLS
482
483 enableInheritURIQueryComponent:
484   initial: false
485
486 aggressiveTileRetentionEnabled:
487   initial: false
488 temporaryTileCohortRetentionEnabled:
489   initial: true
490
491 useImageDocumentForSubframePDF:
492   initial: false
493 dataDetectorTypes:
494   type: DataDetectorTypes
495   initial: DataDetectorTypeNone
496   conditional: DATA_DETECTION
497
498 # Allow SourceBuffers to store up to 304MB each, enough for approximately five minutes
499 # of 1080p video and stereo audio.
500 maximumSourceBufferSize:
501   type: int
502   initial: 318767104
503   conditional: MEDIA_SOURCE
504
505 serviceControlsEnabled:
506   initial: false
507   conditional: SERVICE_CONTROLS
508
509 appleMailPaginationQuirkEnabled:
510   initial: false
511
512 deferredCSSParserEnabled:
513   initial: false
514
515 repaintOutsideLayoutEnabled:
516   initial: false
517
518 httpEquivEnabled:
519   initial: true
520
521 # Some ports (e.g. iOS) might choose to display attachments inline, regardless of whether the response includes the
522 # HTTP header "Content-Disposition: attachment". This setting enables a sandbox around these attachments. The sandbox
523 # enforces all frame sandbox flags (see enum SandboxFlag in SecurityContext.h), and also disables <meta http-equiv>
524 # processing and subframe loading.
525 contentDispositionAttachmentSandboxEnabled:
526   initial: false
527
528 userInterfaceDirectionPolicy:
529   type: UserInterfaceDirectionPolicy
530   initial: UserInterfaceDirectionPolicy::Content
531 systemLayoutDirection:
532   type: TextDirection
533   initial: TextDirection::LTR
534
535 allowContentSecurityPolicySourceStarToMatchAnyProtocol:
536   initial: false
537
538 selectionPaintingWithoutSelectionGapsEnabled:
539   initial: false
540
541 shouldConvertInvalidURLsToBlank:
542   initial: true
543
544 springTimingFunctionEnabled:
545   initial: false
546
547 colorFilterEnabled:
548   initial: false
549   onChange: setNeedsRecalcStyleInAllFrames
550
551 punchOutWhiteBackgroundsInDarkMode:
552   initial: false
553   onChange: setNeedsRecalcStyleInAllFrames
554
555 treatIPAddressAsDomain:
556   initial: false
557
558 mediaPreloadingEnabled:
559   initial: false
560
561 layoutViewportHeightExpansionFactor:
562   type: double
563   initial: 0
564   onChange: setNeedsRecalcStyleInAllFrames
565
566 # Runtime-enabled features
567 visualViewportEnabled:
568   initial: false
569   onChange: setNeedsRecalcStyleInAllFrames
570
571 visualViewportAPIEnabled:
572   initial: false
573
574 CSSOMViewScrollingAPIEnabled:
575   initial: false
576
577 inputEventsEnabled:
578   initial: true
579
580 quickTimePluginReplacementEnabled:
581   initial: defaultQuickTimePluginReplacementEnabled
582 youTubeFlashPluginReplacementEnabled:
583   initial: defaultYouTubeFlashPluginReplacementEnabled
584
585 forcedColorsAreInvertedAccessibilityValue:
586   type: ForcedAccessibilityValue
587   initial: defaultForcedColorsAreInvertedAccessibilityValue
588 forcedDisplayIsMonochromeAccessibilityValue:
589   type: ForcedAccessibilityValue
590   initial: defaultForcedDisplayIsMonochromeAccessibilityValue
591 forcedPrefersReducedMotionAccessibilityValue:
592   type: ForcedAccessibilityValue
593   initial: defaultForcedPrefersReducedMotionAccessibilityValue
594
595 largeImageAsyncDecodingEnabled:
596   initial: true
597 animatedImageAsyncDecodingEnabled:
598   initial: true
599 webkitImageReadyEventEnabled:
600   initial: false
601
602 shouldSuppressTextInputFromEditingDuringProvisionalNavigation:
603   initial: false
604
605 langAttributeAwareFormControlUIEnabled:
606   initial: false
607
608 subresourceIntegrityEnabled:
609   initial: true
610
611 linkPreconnectEnabled:
612   initial: false
613
614 beaconAPIEnabled:
615   initial: false
616
617 geolocationFloorLevelEnabled:
618   initial: true
619
620 constantPropertiesEnabled:
621   initial: false
622
623 viewportFitEnabled:
624   initial: false
625
626 allowMediaContentTypesRequiringHardwareSupportAsFallback:
627   initial: false
628
629 storageAccessAPIEnabled:
630   initial: true
631
632 timeWithoutMouseMovementBeforeHidingControls:
633   type: Seconds
634   initial: 3_s
635
636 fontFallbackPrefersPictographs:
637   initial: false
638   onChange: setNeedsRecalcStyleInAllFrames
639
640 fontLoadTimingOverride:
641   type: FontLoadTimingOverride
642   initial: FontLoadTimingOverride::None
643 shouldIgnoreFontLoadCompletions:
644   initial: false
645
646 paymentRequestEnabled:
647   initial: false
648   conditional: PAYMENT_REQUEST
649 applePayEnabled:
650   initial: false
651   conditional: APPLE_PAY
652 applePayCapabilityDisclosureAllowed:
653   initial: true
654   conditional: APPLE_PAY
655
656 javaEnabled:
657   initial: false
658   getter: isJavaEnabled
659 javaEnabledForLocalFiles:
660   initial: true
661   getter: isJavaEnabledForLocalFiles
662
663 # Unlike the imagesEnabled setting, this only suppresses the network load of
664 # the image URL. A cached image will still be rendered if requested.
665 loadsImagesAutomatically:
666   initial: false
667   onChange: imagesEnabledChanged
668 imagesEnabled:
669   initial: true
670   getter: areImagesEnabled
671   onChange: imagesEnabledChanged
672 scriptEnabled:
673   initial: false
674   getter: isScriptEnabled
675 pluginsEnabled:
676   initial: false
677   getter: arePluginsEnabled
678   onChange: pluginsEnabledChanged
679
680 usesPageCache:
681   initial: false
682   onChange: usesPageCacheChanged
683
684 dnsPrefetchingEnabled:
685   initial: false
686   onChange: dnsPrefetchingEnabledChanged
687
688 backgroundShouldExtendBeyondPage:
689   initial: false
690   onChange: backgroundShouldExtendBeyondPageChanged
691
692 scrollingPerformanceLoggingEnabled:
693   initial: false
694   onChange: scrollingPerformanceLoggingEnabledChanged
695
696 hiddenPageDOMTimerThrottlingEnabled:
697   initial: false
698   onChange: hiddenPageDOMTimerThrottlingStateChanged
699 hiddenPageDOMTimerThrottlingAutoIncreases:
700   initial: false
701   onChange: hiddenPageDOMTimerThrottlingStateChanged
702 hiddenPageCSSAnimationSuspensionEnabled:
703   initial: false
704   onChange: hiddenPageCSSAnimationSuspensionEnabledChanged
705
706 storageBlockingPolicy:
707   type: SecurityOrigin::StorageBlockingPolicy
708   initial: SecurityOrigin::AllowAllStorage
709   onChange: storageBlockingPolicyChanged
710
711 shouldAllowUserInstalledFonts:
712   initial: true
713   onChange: setNeedsRecalcStyleInAllFrames
714
715 # Only set by Layout Tests.
716 mediaTypeOverride:
717   type: String
718   initial: '"screen"'
719   onChange: mediaTypeOverrideChanged
720
721
722 fontRenderingMode:
723   type: FontRenderingMode
724   initial: FontRenderingMode::Normal
725
726 preferMIMETypeForImages:
727   initial: false
728
729 forcePendingWebGLPolicy:
730   initial: false
731   getter: isForcePendingWebGLPolicy
732
733 mediaKeysStorageDirectory:
734   type: String
735
736 mediaDeviceIdentifierStorageDirectory:
737   type: String
738   conditional: MEDIA_STREAM
739
740 # FIXME: This quirk is needed because of Radar 4674537 and 5211271. We need to phase it out once Adobe
741 # can fix the bug from their end.
742 needsAdobeFrameReloadingQuirk:
743   initial: false
744   getter: needsAcrobatFrameReloadingQuirk
745
746 passiveTouchListenersAsDefaultOnDocument:
747   initial: true
748
749 touchEventEmulationEnabled:
750   initial: false
751   getter: isTouchEventEmulationEnabled
752   conditional: TOUCH_EVENTS
753
754 deviceOrientationEventEnabled:
755   type: bool
756   initial: true
757   conditional: DEVICE_ORIENTATION
758
759 shouldEnableTextAutosizingBoost:
760   type: bool
761   initial: false
762   conditional: TEXT_AUTOSIZING
763   onChange: shouldEnableTextAutosizingBoostChanged
764
765 mediaCapabilitiesEnabled:
766   initial: false
767
768 clientCoordinatesRelativeToLayoutViewport:
769   initial: false
770   onChange: setNeedsRecalcStyleInAllFrames
771
772 accessibilityEventsEnabled:
773   initial: true
774   conditional: ACCESSIBILITY_EVENTS
775
776 incompleteImageBorderEnabled:
777   initial: false
778
779 shouldDeferAsynchronousScriptsUntilAfterDocumentLoad:
780   initial: false
781
782 shouldIgnoreMetaViewport:
783   initial: false
784
785 videoQualityIncludesDisplayCompositingEnabled:
786   initial: false
787   conditional: VIDEO
788
789 editableImagesEnabled:
790   initial: false
791
792 adClickAttributionEnabled:
793   initial: false