ContentVisibility: enable the flag by default on stable.

This patch enables CSS content-visibility by default.

R=chrishtr@chromium.org

Bug: 1074371
Change-Id: If51a8a3a48f1779ba11df3ff6f97d01b92147118
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2239296Reviewed-by: Chris Harrelson <chrishtr@chromium.org>
Commit-Queue: vmpstr <vmpstr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#777111}

third_party/blink/renderer/platform/runtime_enabled_features.json5

@@ -413,17 +413,15 @@
     },
     {
       // The main content-visibility feature.
-      // https://wicg.github.io/display-locking/
+      // https://drafts.csswg.org/css-contain/#content-visibility 
       name: "CSSContentVisibility",
-      status: "experimental",
-      implied_by: ["CSSContentVisibilityHiddenMatchable"]
+      status: "stable",
     },
     {
       // The content-visibility activation event which will be replaced by
       // the beforematch event. When beforematch is available, this feaure
       // will be removed.
-      name: "CSSContentVisibilityActivationEvent",
-      implied_by: ["CSSContentVisibility"]
+      name: "CSSContentVisibilityActivationEvent"
     },
     {
       // The content-visibility: hidden-matchable feature. This is a planned
@@ -459,7 +457,6 @@
       // Support for CSS contain-intrinsic-size property.
       // https://wicg.github.io/display-locking/contain-intrinsic-size.html
       name: "CSSIntrinsicSize",
-      implied_by: ["CSSContentVisibility"],
       status: "stable",
     },
     {

third_party/blink/web_tests/fast/dom/Window/property-access-on-cached-window-after-frame-navigated-expected.txt

@@ -149,7 +149,6 @@ PASS oldChildWindow.onportalactivate is newChildWindow.onportalactivate
 PASS oldChildWindow.onprogress is newChildWindow.onprogress
 PASS oldChildWindow.onratechange is newChildWindow.onratechange
 PASS oldChildWindow.onrejectionhandled is newChildWindow.onrejectionhandled
-PASS oldChildWindow.onrendersubtreeactivation is newChildWindow.onrendersubtreeactivation
 PASS oldChildWindow.onreset is newChildWindow.onreset
 PASS oldChildWindow.onresize is newChildWindow.onresize
 PASS oldChildWindow.onscreenschange is newChildWindow.onscreenschange

third_party/blink/web_tests/fast/dom/Window/property-access-on-cached-window-after-frame-removed-and-gced-expected.txt

@@ -116,7 +116,6 @@ PASS childWindow.onportalactivate is null
 PASS childWindow.onprogress is null
 PASS childWindow.onratechange is null
 PASS childWindow.onrejectionhandled is null
-PASS childWindow.onrendersubtreeactivation is null
 PASS childWindow.onreset is null
 PASS childWindow.onresize is null
 PASS childWindow.onscreenschange is null

third_party/blink/web_tests/fast/dom/Window/property-access-on-cached-window-after-frame-removed-expected.txt

@@ -116,7 +116,6 @@ PASS childWindow.onportalactivate is null
 PASS childWindow.onprogress is null
 PASS childWindow.onratechange is null
 PASS childWindow.onrejectionhandled is null
-PASS childWindow.onrendersubtreeactivation is null
 PASS childWindow.onreset is null
 PASS childWindow.onresize is null
 PASS childWindow.onscreenschange is null

third_party/blink/web_tests/virtual/stable/webexposed/css-properties-as-js-properties-expected.txt

@@ -114,6 +114,7 @@ columns
 contain
 containIntrinsicSize
 content
+contentVisibility
 counterIncrement
 counterReset
 cssFloat

third_party/blink/web_tests/virtual/stable/webexposed/css-property-listing-expected.txt

@@ -149,6 +149,7 @@ All changes to this list should go through Blink's feature review process: http:
     contain
     contain-intrinsic-size
     content
+    content-visibility
     counter-increment
     counter-reset
     cursor

third_party/blink/web_tests/webexposed/element-instance-property-listing-expected.txt

@@ -240,7 +240,6 @@ namespace http://www.w3.org/1999/xhtml
     property onpointerup
     property onprogress
     property onratechange
-    property onrendersubtreeactivation
     property onreset
     property onresize
     property onscroll
@@ -1432,7 +1431,6 @@ namespace http://www.w3.org/2000/svg
     property onpointerup
     property onprogress
     property onratechange
-    property onrendersubtreeactivation
     property onreset
     property onresize
     property onscroll

third_party/blink/web_tests/webexposed/global-interface-listing-expected.txt

@@ -1648,7 +1648,6 @@ interface Document : Node
     getter onprogress
     getter onratechange
     getter onreadystatechange
-    getter onrendersubtreeactivation
     getter onreset
     getter onresize
     getter onresume
@@ -1849,7 +1848,6 @@ interface Document : Node
     setter onprogress
     setter onratechange
     setter onreadystatechange
-    setter onrendersubtreeactivation
     setter onreset
     setter onresize
     setter onresume
@@ -3017,7 +3015,6 @@ interface HTMLElement : Element
     getter onpointerup
     getter onprogress
     getter onratechange
-    getter onrendersubtreeactivation
     getter onreset
     getter onresize
     getter onscroll
@@ -3134,7 +3131,6 @@ interface HTMLElement : Element
     setter onpointerup
     setter onprogress
     setter onratechange
-    setter onrendersubtreeactivation
     setter onreset
     setter onresize
     setter onscroll
@@ -4834,7 +4830,6 @@ interface MathMLElement : Element
     getter onpointerup
     getter onprogress
     getter onratechange
-    getter onrendersubtreeactivation
     getter onreset
     getter onresize
     getter onscroll
@@ -4933,7 +4928,6 @@ interface MathMLElement : Element
     setter onpointerup
     setter onprogress
     setter onratechange
-    setter onrendersubtreeactivation
     setter onreset
     setter onresize
     setter onscroll
@@ -6659,10 +6653,6 @@ interface RemotePlayback : EventTarget
     setter onconnect
     setter onconnecting
     setter ondisconnect
-interface RenderSubtreeActivationEvent : Event
-    attribute @@toStringTag
-    getter activatedElement
-    method constructor
 interface ReportingObserver
     attribute @@toStringTag
     method constructor
@@ -6950,7 +6940,6 @@ interface SVGElement : Element
     getter onpointerup
     getter onprogress
     getter onratechange
-    getter onrendersubtreeactivation
     getter onreset
     getter onresize
     getter onscroll
@@ -7051,7 +7040,6 @@ interface SVGElement : Element
     setter onpointerup
     setter onprogress
     setter onratechange
-    setter onrendersubtreeactivation
     setter onreset
     setter onresize
     setter onscroll
@@ -11823,7 +11811,6 @@ interface webkitURL
     getter onprogress
     getter onratechange
     getter onrejectionhandled
-    getter onrendersubtreeactivation
     getter onreset
     getter onresize
     getter onscreenschange
@@ -12027,7 +12014,6 @@ interface webkitURL
     setter onprogress
     setter onratechange
     setter onrejectionhandled
-    setter onrendersubtreeactivation
     setter onreset
     setter onresize
     setter onscreenschange