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

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

 /*
  * 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 110 matching lines @@
 #include "core/testing/InternalSettings.h"
 #include "core/testing/LayerRect.h"
 #include "core/testing/LayerRectList.h"
 #include "core/testing/MockHyphenation.h"
 #include "core/testing/PrivateScriptTest.h"
 #include "core/testing/TypeConversions.h"
 #include "core/testing/UnionTypesTest.h"
 #include "core/workers/WorkerThread.h"
 #include "gpu/command_buffer/client/gles2_interface.h"
 #include "platform/Cursor.h"
+#include "platform/Histogram.h"
 #include "platform/Language.h"
 #include "platform/PlatformKeyboardEvent.h"
 #include "platform/RuntimeEnabledFeatures.h"
 #include "platform/TraceEvent.h"
 #include "platform/geometry/IntRect.h"
 #include "platform/geometry/LayoutRect.h"
 #include "platform/graphics/GraphicsLayer.h"
 #include "platform/heap/Handle.h"
 #include "platform/inspector_protocol/FrontendChannel.h"
 #include "platform/scroll/ProgrammaticScrollAnimator.h"
@@ skipping 238 matching lines @@
         exceptionState.throwDOMException(InvalidAccessError, "Must supply document to check");
         return;
     }
 
     if (doc->layoutViewItem().isNull())
         return;
 
     doc->layoutViewItem().clearHitTestCache();
 }
 
+int Internals::histogramCount(const String& name, int bucket, ExceptionState& exceptionState) const
+{
+    int32_t count;
+    if (!EnumerationHistogram::GetHistogramCount(name.utf8().data(), bucket, &count)) {
+        exceptionState.throwDOMException(InvalidAccessError, "Could not find histogram");
+        return 0;
+    }
+    return count;
+}
+
 bool Internals::isPreloaded(const String& url)
 {
     return isPreloadedBy(url, contextDocument());
 }
 
 bool Internals::isPreloadedBy(const String& url, Document* document)
 {
     if (!document)
         return false;
     return document->fetcher()->isPreloaded(document->completeURL(url));
@@ skipping 2231 matching lines @@
 }
 
 String Internals::getProgrammaticScrollAnimationState(Node* node) const
 {
     if (ScrollableArea* scrollableArea = scrollableAreaForNode(node))
         return scrollableArea->programmaticScrollAnimator().runStateAsText();
     return String();
 }
 
 } // namespace blink