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

content/browser/renderer_host/input/gesture_event_queue.h

 // Copyright 2014 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_BROWSER_RENDERER_HOST_INPUT_GESTURE_EVENT_QUEUE_H_
 #define CONTENT_BROWSER_RENDERER_HOST_INPUT_GESTURE_EVENT_QUEUE_H_
 
 #include <stddef.h>
 
 #include <deque>
@@ skipping 95 matching lines @@
 
   bool empty() const {
     return coalesced_gesture_events_.empty() &&
            debouncing_deferral_queue_.empty();
   }
 
   void set_debounce_interval_time_ms_for_testing(int interval_ms) {
     debounce_interval_ = base::TimeDelta::FromMilliseconds(interval_ms);
   }
 
+  bool FlingInProgress() { return fling_in_progress_; }

[dtapuska, 2016/04/27 19:05:13]

const 

+
  private:
   friend class GestureEventQueueTest;
   friend class MockRenderWidgetHost;
 
   // TODO(mohsen): There are a bunch of ShouldForward.../ShouldDiscard...
   // methods that are getting confusing. This should be somehow fixed. Maybe
   // while refactoring GEQ: http://crbug.com/148443.
 
   // Inovked on the expiration of the debounce interval to release
   // deferred events.
@@ skipping 76 matching lines @@
   // Time window in which to debounce scroll/fling ends. Note that an interval
   // of zero effectively disables debouncing.
   base::TimeDelta debounce_interval_;
 
   DISALLOW_COPY_AND_ASSIGN(GestureEventQueue);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_INPUT_GESTURE_EVENT_QUEUE_H_