Add UMA metric for tracking listeners for blocking touch while fling is happening

content/renderer/android/synchronous_compositor_filter.h

 // Copyright 2015 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 CONTENT_RENDERER_ANDROID_SYNCHRONOUS_COMPOSITOR_FILTER_H_
 #define CONTENT_RENDERER_ANDROID_SYNCHRONOUS_COMPOSITOR_FILTER_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 48 matching lines @@
   void UnregisterBeginFrameSource(int routing_id,
                                   SynchronousCompositorExternalBeginFrameSource*
                                       begin_frame_source) override;
 
   // InputHandlerManagerClient overrides.
   void SetBoundHandler(const Handler& handler) override;
   void DidAddInputHandler(int routing_id) override;
   void DidRemoveInputHandler(int routing_id) override;
   void DidOverscroll(int routing_id,
                      const DidOverscrollParams& params) override;
+  void DidStartFlinging(int routing_id) override;
   void DidStopFlinging(int routing_id) override;
   void NotifyInputEventHandled(int routing_id,
                                blink::WebInputEvent::Type type) override;
 
   // SynchronousInputHandlerProxyClient overrides.
   void DidAddSynchronousHandlerProxy(
       int routing_id,
       ui::SynchronousInputHandlerProxy* synchronous_input_handler_proxy)
       override;
   void DidRemoveSynchronousHandlerProxy(int routing_id) override;
@@ skipping 37 matching lines @@
   };
   using EntryMap = base::hash_map<int, Entry>;
   EntryMap entry_map_;
 
   DISALLOW_COPY_AND_ASSIGN(SynchronousCompositorFilter);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_ANDROID_SYNCHRONOUS_COMPOSITOR_FILTER_H_