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

content/renderer/input/input_handler_wrapper.cc

 // Copyright 2013 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/input/input_handler_wrapper.h"
 
 #include "base/command_line.h"
 #include "base/location.h"
 #include "content/common/input/did_overscroll_params.h"
 #include "content/public/common/content_switches.h"
@@ skipping 33 matching lines @@
 }
 
 void InputHandlerWrapper::WillShutdown() {
   input_handler_manager_->RemoveInputHandler(routing_id_);
 }
 
 blink::WebGestureCurve* InputHandlerWrapper::CreateFlingAnimationCurve(
     blink::WebGestureDevice deviceSource,
     const blink::WebFloatPoint& velocity,
     const blink::WebSize& cumulative_scroll) {
+  DidStartFlinging();
   return blink::Platform::current()->createFlingAnimationCurve(
       deviceSource, velocity, cumulative_scroll);
 }
 
 void InputHandlerWrapper::DidOverscroll(
     const gfx::Vector2dF& accumulated_overscroll,
     const gfx::Vector2dF& latest_overscroll_delta,
     const gfx::Vector2dF& current_fling_velocity,
     const gfx::PointF& causal_event_viewport_point) {
   DidOverscrollParams params;
   params.accumulated_overscroll = accumulated_overscroll;
   params.latest_overscroll_delta = latest_overscroll_delta;
   params.current_fling_velocity = current_fling_velocity;
   params.causal_event_viewport_point = causal_event_viewport_point;
   input_handler_manager_->DidOverscroll(routing_id_, params);
 }
 
+void InputHandlerWrapper::DidStartFlinging() {
+  input_handler_manager_->DidStartFlinging(routing_id_);
+}
+
 void InputHandlerWrapper::DidStopFlinging() {
   input_handler_manager_->DidStopFlinging(routing_id_);
 }
 
 void InputHandlerWrapper::DidAnimateForInput() {
   input_handler_manager_->DidAnimateForInput();
 }
 
 }  // namespace content