Bundle DidOverscrollParams with the InputEventAck

content/renderer/input/input_event_filter.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_RENDERER_INPUT_INPUT_EVENT_FILTER_H_
 #define CONTENT_RENDERER_INPUT_INPUT_EVENT_FILTER_H_
 
 #include <queue>
 #include <set>
 
@@ skipping 52 matching lines @@
   virtual void OnFilterAdded(IPC::Channel* channel) OVERRIDE;
   virtual void OnFilterRemoved() OVERRIDE;
   virtual void OnChannelClosing() OVERRIDE;
   virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
 
  private:
   virtual ~InputEventFilter();
 
   void ForwardToMainListener(const IPC::Message& message);
   void ForwardToHandler(const IPC::Message& message);
-  void SendACK(blink::WebInputEvent::Type type,
-               InputEventAckState ack_result,
-               const ui::LatencyInfo& latency_info,
-               int routing_id);
-  void SendMessage(const IPC::Message& message);
-  void SendMessageOnIOThread(const IPC::Message& message);
+  void SendMessage(scoped_ptr<IPC::Message> message);
+  void SendMessageOnIOThread(scoped_ptr<IPC::Message> message);
 
   scoped_refptr<base::MessageLoopProxy> main_loop_;
   IPC::Listener* main_listener_;
 
   // The sender_ only gets invoked on the thread corresponding to io_loop_.
   scoped_refptr<base::MessageLoopProxy> io_loop_;
   IPC::Sender* sender_;
 
   // The handler_ only gets Run on the thread corresponding to target_loop_.
   scoped_refptr<base::MessageLoopProxy> target_loop_;
   Handler handler_;
 
   // Protects access to routes_.
   base::Lock routes_lock_;
 
   // Indicates the routing_ids for which input events should be filtered.
   std::set<int> routes_;
 
   // Specifies whether overscroll notifications are forwarded to the host.
   bool overscroll_notifications_enabled_;
+
+  // Used to intercept overscroll notifications while an event is being
+  // dispatched.  If the event causes overscroll, the overscroll metadata can be
+  // bundled in the event ack, saving an IPC.  Note that we must continue
+  // supporting overscroll IPC notifications due to fling animation updates.
+  scoped_ptr<DidOverscrollParams>* current_overscroll_params_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_INPUT_INPUT_EVENT_FILTER_H_