Signal input flush when all flings have terminated

content/browser/renderer_host/input/input_router_impl.h

Index: content/browser/renderer_host/input/input_router_impl.h
diff --git a/content/browser/renderer_host/input/input_router_impl.h b/content/browser/renderer_host/input/input_router_impl.h
index ab5058329547e51cd7a443674d937d5109671aee..04a34c751449cd0f8f25f65d40d19583844e9b99 100644
--- a/content/browser/renderer_host/input/input_router_impl.h
+++ b/content/browser/renderer_host/input/input_router_impl.h
@@ -56,7 +56,6 @@ class CONTENT_EXPORT InputRouterImpl
   ~InputRouterImpl() override;
 
   // InputRouter
-  void Flush() override;
   bool SendInput(scoped_ptr<IPC::Message> message) override;
   void SendMouseEvent(const MouseEventWithLatencyInfo& mouse_event) override;
   void SendWheelEvent(
@@ -69,6 +68,7 @@ class CONTENT_EXPORT InputRouterImpl
   void SendTouchEvent(const TouchEventWithLatencyInfo& touch_event) override;
   const NativeWebKeyboardEvent* GetLastKeyboardEvent() const override;
   void OnViewUpdated(int view_flags) override;
+  void RequestNotificationWhenFlushed() override;
   bool HasPendingEvents() const override;
 
   // IPC::Listener
@@ -130,6 +130,7 @@ private:
   void OnSelectMessageAck();
   void OnHasTouchEventHandlers(bool has_handlers);
   void OnSetTouchAction(TouchAction touch_action);
+  void OnFlingingStopped();
 
   // Indicates the source of an ack provided to |ProcessInputEventAck()|.
   // The source is tracked by |current_ack_source_|, which aids in ack routing.
@@ -181,8 +182,6 @@ private:
   // all events have been dispatched (i.e., |HasPendingEvents()| is false).
   void SignalFlushedIfNecessary();
 
-  bool IsInOverscrollGesture() const;
-
   int routing_id() const { return routing_id_; }
 
 
@@ -248,6 +247,11 @@ private:
   // to the client_ after all events have been dispatched/acked.
   bool flush_requested_;
 
+  // Whether there are any active flings in the renderer. As the fling
+  // end notification is asynchronous, we use a count rather than a boolean
+  // to avoid races in bookkeeping when starting a new fling.
+  int active_fling_count_;
+
   TouchEventQueue touch_event_queue_;
   GestureEventQueue gesture_event_queue_;
   TouchActionFilter touch_action_filter_;