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

content/renderer/input/input_handler_manager.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_manager.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/location.h"
@@ skipping 203 matching lines @@
   if (it == input_handlers_.end()) {
     TRACE_EVENT1("input", "InputHandlerManager::HandleInputEvent",
                  "result", "NoInputHandlerFound");
     // Oops, we no longer have an interested input handler..
     return INPUT_EVENT_ACK_STATE_NOT_CONSUMED;
   }
 
   TRACE_EVENT1("input", "InputHandlerManager::HandleInputEvent",
                "result", "EventSentToInputHandlerProxy");
   InputHandlerProxy* proxy = it->second->input_handler_proxy();
+  if (blink::WebInputEvent::isTouchEventType(input_event->type)) {

[dtapuska, 2016/05/05 20:22:21]

this seems odd to repeatedly set a state on touch events. Shouldn't the state
always be consistent irrespective of the input type that is processed?

Shouldn't the state just be replicated to the associated client all the time?

+    client_->SetIsFlinging(proxy->isFlinging());
+  }
+
   InputEventAckState input_event_ack_state = InputEventDispositionToAck(
       proxy->HandleInputEventWithLatencyInfo(*input_event, latency_info));
   switch (input_event_ack_state) {
     case INPUT_EVENT_ACK_STATE_CONSUMED:
       renderer_scheduler_->DidHandleInputEventOnCompositorThread(
           *input_event,
           RendererScheduler::InputEventState::EVENT_CONSUMED_BY_COMPOSITOR);
       break;
     case INPUT_EVENT_ACK_STATE_NOT_CONSUMED:
       renderer_scheduler_->DidHandleInputEventOnCompositorThread(
@@ skipping 13 matching lines @@
 
 void InputHandlerManager::DidStopFlinging(int routing_id) {
   client_->DidStopFlinging(routing_id);
 }
 
 void InputHandlerManager::DidAnimateForInput() {
   renderer_scheduler_->DidAnimateForInputOnCompositorThread();
 }
 
 }  // namespace content