UMA metrics for use count of wheel and touch scrolls.

cc/trees/layer_tree_host_common.h

 // Copyright 2011 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_COMMON_H_
 #define CC_TREES_LAYER_TREE_HOST_COMMON_H_
 
 #include <stddef.h>
 
 #include <limits>
@@ skipping 157 matching lines @@
   // current page scale, the two must be committed at the same time to prevent
   // clamping.
   LayerTreeHostCommon::ScrollUpdateInfo inner_viewport_scroll;
 
   std::vector<LayerTreeHostCommon::ScrollUpdateInfo> scrolls;
   float page_scale_delta;
   gfx::Vector2dF elastic_overscroll_delta;
   float top_controls_delta;
   std::vector<LayerTreeHostCommon::ScrollbarsUpdateInfo> scrollbars;
   std::vector<std::unique_ptr<SwapPromise>> swap_promises;
+  bool has_scrolled_by_wheel;
+  bool has_scrolled_by_touch;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(ScrollAndScaleSet);
 };
 
 template <typename Function>
 void LayerTreeHostCommon::CallFunctionForEveryLayer(LayerTreeHost* host,
                                                     const Function& function) {
   for (auto* layer : *host) {
     function(layer);
@@ skipping 12 matching lines @@
     function(tree_impl->LayerById(id));
   }
 }
 
 CC_EXPORT PropertyTrees* GetPropertyTrees(Layer* layer);
 CC_EXPORT PropertyTrees* GetPropertyTrees(LayerImpl* layer);
 
 }  // namespace cc
 
 #endif  // CC_TREES_LAYER_TREE_HOST_COMMON_H_