Implement the overflow-anchor CSS property as an opt-out for ScrollAnchoring

third_party/WebKit/Source/core/frame/UseCounter.cpp

 /*
  * 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
@@ skipping 547 matching lines @@
     case CSSPropertyColumnRuleWidth: return 528;
     case CSSPropertyColumnSpan: return 529;
     case CSSPropertyColumnWidth: return 530;
     case CSSPropertyColumns: return 531;
     case CSSPropertyApplyAtRule: return 532;
     case CSSPropertyFontVariantCaps: return 533;
     case CSSPropertyHyphens: return 534;
     case CSSPropertyFontVariantNumeric: return 535;
     case CSSPropertyTextSizeAdjust: return 536;
     case CSSPropertyAliasWebkitTextSizeAdjust: return 537;
+    case CSSPropertyOverflowAnchor: return 538;

[ymalik, 2016/07/13 00:47:34]

Need to update histogram.xml. Waiting for
https://codereview.chromium.org/2140173002/ to land.

 
     // 1. Add new features above this line (don't change the assigned numbers of the existing
     // items).
     // 2. Update maximumCSSSampleId() with the new maximum value.
     // 3. Run the update_use_counter_css.py script in
     // chromium/src/tools/metrics/histograms to update the UMA histogram names.
 
     case CSSPropertyInvalid:
         ASSERT_NOT_REACHED();
         return 0;
     }
 
     ASSERT_NOT_REACHED();
     return 0;
 }
 
 
-static int maximumCSSSampleId() { return 537; }
+static int maximumCSSSampleId() { return 538; }
 
 static EnumerationHistogram& featureObserverHistogram()
 {
     DEFINE_STATIC_LOCAL(EnumerationHistogram, histogram, ("WebCore.FeatureObserver", UseCounter::NumberOfFeatures));
     return histogram;
 }
 
 void UseCounter::muteForInspector()
 {
     UseCounter::m_muteCount++;
@@ skipping 181 matching lines @@
 UseCounter* UseCounter::getFrom(const StyleSheetContents* sheetContents)
 {
     // FIXME: We may want to handle stylesheets that have multiple owners
     //        https://crbug.com/242125
     if (sheetContents && sheetContents->hasSingleOwnerNode())
         return getFrom(sheetContents->singleOwnerDocument());
     return 0;
 }
 
 } // namespace blink