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

content/renderer/input/input_event_filter.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_event_filter.h"
 
 #include <utility>
 
 #include "base/auto_reset.h"
 #include "base/bind.h"
@@ skipping 41 matching lines @@
       target_task_runner_(target_task_runner),
       current_overscroll_params_(NULL) {
   DCHECK(target_task_runner_.get());
 }
 
 void InputEventFilter::SetBoundHandler(const Handler& handler) {
   DCHECK(main_task_runner_->BelongsToCurrentThread());
   handler_ = handler;
 }
 
+void InputEventFilter::SetIsFlingingInMainThreadEventQueue(int routing_id,
+                                                           bool is_flinging) {
+  RouteQueueMap::iterator iter = route_queues_.find(routing_id);
+  if (iter == route_queues_.end() || !iter->second)
+    return;
+
+  iter->second->set_is_flinging(is_flinging);
+}
+
 void InputEventFilter::DidAddInputHandler(int routing_id) {
   base::AutoLock locked(routes_lock_);
   routes_.insert(routing_id);
   route_queues_[routing_id].reset(new MainThreadEventQueue(routing_id, this));
 }
 
 void InputEventFilter::DidRemoveInputHandler(int routing_id) {
   base::AutoLock locked(routes_lock_);
   routes_.erase(routing_id);
   route_queues_.erase(routing_id);
 }
 
 void InputEventFilter::DidOverscroll(int routing_id,
                                      const DidOverscrollParams& params) {
   if (current_overscroll_params_) {
     current_overscroll_params_->reset(new DidOverscrollParams(params));
     return;
   }
 
   SendMessage(std::unique_ptr<IPC::Message>(
       new InputHostMsg_DidOverscroll(routing_id, params)));
 }
 
+void InputEventFilter::DidStartFlinging(int routing_id) {
+  SetIsFlingingInMainThreadEventQueue(routing_id, true);
+}
+
 void InputEventFilter::DidStopFlinging(int routing_id) {
+  SetIsFlingingInMainThreadEventQueue(routing_id, false);
   SendMessage(base::WrapUnique(new InputHostMsg_DidStopFlinging(routing_id)));
 }
 
 void InputEventFilter::NotifyInputEventHandled(
     int routing_id,
     blink::WebInputEvent::Type type) {
   DCHECK(target_task_runner_->BelongsToCurrentThread());
   RouteQueueMap::iterator iter = route_queues_.find(routing_id);
   if (iter == route_queues_.end() || !iter->second)
     return;
@@ skipping 126 matching lines @@
     InputEventDispatchType dispatch_type) {
   TRACE_EVENT_INSTANT0(
       "input", "InputEventFilter::ForwardToHandler::SendEventToMainThread",
       TRACE_EVENT_SCOPE_THREAD);
   IPC::Message new_msg =
       InputMsg_HandleInputEvent(routing_id, event, latency_info, dispatch_type);
   main_task_runner_->PostTask(FROM_HERE, base::Bind(main_listener_, new_msg));
 }
 
 }  // namespace content