Add UMA metrics for root scroller intervention to track forcing passive breakage.

third_party/WebKit/Source/core/testing/Internals.idl

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  * Copyright (C) 2013 Apple 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.
@@ skipping 48 matching lines @@
     [RaisesException] boolean hasSelectorForIdInShadow(Element host, DOMString id);
     [RaisesException] boolean hasSelectorForClassInShadow(Element host, DOMString className);
     [RaisesException] boolean hasSelectorForAttributeInShadow(Element host, DOMString attributeName);
     [RaisesException] unsigned short compareTreeScopePosition(Node treeScope1, Node treeScope2);
     [RaisesException] unsigned long updateStyleAndReturnAffectedElementCount();
     [RaisesException] unsigned long needsLayoutCount();
     [RaisesException] unsigned long hitTestCount(Document document);
     [RaisesException] unsigned long hitTestCacheHits(Document document);
     [RaisesException] Element? elementFromPoint(Document document, double x, double y, boolean ignoreClipping, boolean allowChildFrameContent);
     [RaisesException] void clearHitTestCache(Document document);
+    [RaisesException] long histogramCount(DOMString name, long bucket);
 
     // Animation testing.
     [RaisesException] void pauseAnimations(double pauseTime);
     bool isCompositedAnimation(Animation animation);
     void disableCompositedAnimation(Animation animation);
     void disableCSSAdditiveAnimations();
 
     // Modifies m_desiredFrameStartTime in BitmapImage to advance the next frame time
     // for testing whether animated images work properly.
     [RaisesException] void advanceTimeForImage(Element image, double deltaTimeInSeconds);
@@ skipping 266 matching lines @@
 
     void setMediaElementNetworkState(HTMLMediaElement element, long state);
 
     // TODO(liberato): remove once autoplay gesture override experiment concludes.
     void triggerAutoplayViewportCheck(HTMLMediaElement mediaElement);
 
     DOMString getScrollAnimationState(Node node);
 
     DOMString getProgrammaticScrollAnimationState(Node node);
 };