UMA metrics for use count of wheel and touch scrolls.

cc/trees/layer_tree_host_client.h

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CC_TREES_LAYER_TREE_HOST_CLIENT_H_
 #define CC_TREES_LAYER_TREE_HOST_CLIENT_H_
 
 #include <memory>
 
 #include "base/memory/ref_counted.h"
@@ skipping 25 matching lines @@
   // state. (The "compositing state" will result in a mutated layer tree on the
   // LayerTreeHost via additional interface indirections which lead back to
   // mutations on the LayerTreeHost.)
   virtual void UpdateLayerTreeHost() = 0;
   virtual void ApplyViewportDeltas(
       const gfx::Vector2dF& inner_delta,
       const gfx::Vector2dF& outer_delta,
       const gfx::Vector2dF& elastic_overscroll_delta,
       float page_scale,
       float top_controls_delta) = 0;
+  virtual void RecordWheelAndTouchScrollingCount(
+      bool has_scrolled_by_wheel,
+      bool has_scrolled_by_touch) = 0;
   // Request an CompositorFrameSink from the client. When the client has one it
   // should call LayerTreeHost::SetCompositorFrameSink.  This will result in
   // either DidFailToInitializeCompositorFrameSink or
   // DidInitializeCompositorFrameSink being called.
   virtual void RequestNewCompositorFrameSink() = 0;
   virtual void DidInitializeCompositorFrameSink() = 0;
   virtual void DidFailToInitializeCompositorFrameSink() = 0;
   virtual void WillCommit() = 0;
   virtual void DidCommit() = 0;
   virtual void DidCommitAndDrawFrame() = 0;
   virtual void DidReceiveCompositorFrameAck() = 0;
   virtual void DidCompletePageScaleAnimation() = 0;
 
  protected:
   virtual ~LayerTreeHostClient() {}
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_LAYER_TREE_HOST_CLIENT_H_