Remove HistogramSupport abstraction layer

Source/core/rendering/RenderLayerStackingNode.cpp

Index: Source/core/rendering/RenderLayerStackingNode.cpp
diff --git a/Source/core/rendering/RenderLayerStackingNode.cpp b/Source/core/rendering/RenderLayerStackingNode.cpp
index d5a13c03cbb06a0f61fe40c0f146bf18154ae3db..80276d8dfb03188389d641c23a8840dcd9fced4f 100644
--- a/Source/core/rendering/RenderLayerStackingNode.cpp
+++ b/Source/core/rendering/RenderLayerStackingNode.cpp
@@ -44,10 +44,10 @@
 #include "config.h"
 #include "core/rendering/RenderLayerStackingNode.h"
 
-#include "core/platform/HistogramSupport.h"
 #include "core/rendering/RenderLayer.h"
 #include "core/rendering/RenderLayerCompositor.h"
 #include "core/rendering/RenderView.h"
+#include "public/platform/Platform.h"
 
 namespace WebCore {
 
@@ -625,7 +625,7 @@ bool RenderLayerStackingNode::setNeedsToBeStackingContainer(bool needsToBeStacki
     // containers some point. This should be recorded at most once per
     // RenderLayer, so we check m_needsToBeStackingContainerHasBeenRecorded.
     if (layer()->acceleratedCompositingForOverflowScrollEnabled() && !m_needsToBeStackingContainerHasBeenRecorded) {
-        HistogramSupport::histogramEnumeration("Renderer.CompositedScrolling", RenderLayer::NeedsToBeStackingContainerBucket, RenderLayer::CompositedScrollingHistogramMax);
+        WebKit::Platform::current()->histogramEnumeration("Renderer.CompositedScrolling", RenderLayer::NeedsToBeStackingContainerBucket, RenderLayer::CompositedScrollingHistogramMax);
         m_needsToBeStackingContainerHasBeenRecorded = true;
     }