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

content/renderer/android/synchronous_compositor_filter.cc

 // 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.
 
 #include "content/renderer/android/synchronous_compositor_filter.h"
 
 #include <utility>
 
 #include "base/callback.h"
 #include "base/stl_util.h"
@@ skipping 255 matching lines @@
   DCHECK(compositor_task_runner_->BelongsToCurrentThread());
   DCHECK(ContainsKey(entry_map_, routing_id));
   Entry& entry = entry_map_[routing_id];
 
   if (entry.IsReady())
     UnregisterObjects(routing_id);
   entry.synchronous_input_handler_proxy = nullptr;
   RemoveEntryIfNeeded(routing_id);
 }
 
+void SynchronousCompositorFilter::DidStartFlinging(bool is_on_impl) {}
+
 SynchronousCompositorFilter::Entry::Entry()
     : begin_frame_source(nullptr),
       output_surface(nullptr),
       synchronous_input_handler_proxy(nullptr) {}
 
 bool SynchronousCompositorFilter::Entry::IsReady() {
   return begin_frame_source && synchronous_input_handler_proxy;
 }
 
 }  // namespace content