Don't restart the hang renderer timeout on messages ack'd from the compositor thread.

content/browser/renderer_host/input/input_router_client.h

 // 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.
 
 #ifndef CONTENT_BROWSER_RENDERER_HOST_INPUT_INPUT_ROUTER_CLIENT_H_
 #define CONTENT_BROWSER_RENDERER_HOST_INPUT_INPUT_ROUTER_CLIENT_H_
 
 #include "content/browser/renderer_host/event_with_latency_info.h"
 #include "content/common/content_export.h"
+#include "content/common/input/input_event_ack_source.h"
 #include "content/common/input/input_event_ack_state.h"
 #include "content/public/browser/native_web_keyboard_event.h"
 #include "third_party/WebKit/public/web/WebInputEvent.h"
 
 namespace ui {
 class LatencyInfo;
 struct DidOverscrollParams;
 }
 
 namespace content {
 
 class CONTENT_EXPORT InputRouterClient {
  public:
   virtual ~InputRouterClient() {}
 
   // Called just prior to events being sent to the renderer, giving the client
   // a chance to perform in-process event filtering.
   // The returned disposition will yield the following behavior:
   //   * |NOT_CONSUMED| will result in |input_event| being sent as usual.
   //   * |CONSUMED| or |NO_CONSUMER_EXISTS| will trigger the appropriate ack.
   //   * |UNKNOWN| will result in |input_event| being dropped.
   virtual InputEventAckState FilterInputEvent(
       const blink::WebInputEvent& input_event,
       const ui::LatencyInfo& latency_info) = 0;
 
   // Called each time a WebInputEvent IPC is sent.
   virtual void IncrementInFlightEventCount(blink::WebInputEvent::Type type) = 0;
 
   // Called each time a WebInputEvent ACK IPC is received.
-  virtual void DecrementInFlightEventCount() = 0;
+  virtual void DecrementInFlightEventCount(InputEventAckSource ack_source) = 0;
 
   // Called when the renderer notifies that it has touch event handlers.
   virtual void OnHasTouchEventHandlers(bool has_handlers) = 0;
 
   // Called when the router has finished flushing all events queued at the time
   // of the call to Flush.  The call will typically be asynchronous with
   // respect to the call to |Flush| on the InputRouter.
   virtual void DidFlush() = 0;
 
   // Called when the router has received an overscroll notification from the
   // renderer.
   virtual void DidOverscroll(const ui::DidOverscrollParams& params) = 0;
 
   // Called when a renderer fling has terminated.
   virtual void DidStopFlinging() = 0;
 
   // Called when the input router generates an event. It is intended that the
   // client will do some processing on |gesture_event| and then send it back
   // to the InputRouter via SendGestureEvent.
   virtual void ForwardGestureEventWithLatencyInfo(
       const blink::WebGestureEvent& gesture_event,
       const ui::LatencyInfo& latency_info) = 0;
 };
 
 } // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_INPUT_INPUT_ROUTER_CLIENT_H_