Add HandleInputEventAck message to allow out-of-process plugins to respond to user gestures.

ppapi/proxy/ppp_input_event_proxy.h

 // Copyright (c) 2012 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 PPAPI_PROXY_PPP_INPUT_EVENT_PROXY_H_
 #define PPAPI_PROXY_PPP_INPUT_EVENT_PROXY_H_
 
 #include "ppapi/c/pp_instance.h"
+#include "ppapi/c/pp_time.h"
 #include "ppapi/c/ppp_input_event.h"
 #include "ppapi/proxy/interface_proxy.h"
 
 namespace ppapi {
 
 struct InputEventData;
 
 namespace proxy {
 
 class PPP_InputEvent_Proxy : public InterfaceProxy {
  public:
   PPP_InputEvent_Proxy(Dispatcher* dispatcher);
   virtual ~PPP_InputEvent_Proxy();
 
   static const Info* GetInfo();
 
   // InterfaceProxy implementation.
   virtual bool OnMessageReceived(const IPC::Message& msg);
 
  private:
   // Message handlers.
   void OnMsgHandleInputEvent(PP_Instance instance,
                              const ppapi::InputEventData& data);
   void OnMsgHandleFilteredInputEvent(PP_Instance instance,
                                      const ppapi::InputEventData& data,
                                      PP_Bool* result);
 
+  void HandleInputEventAck(PP_Instance instance, PP_TimeTicks timestamp);
+
   // When this proxy is in the plugin side, this value caches the interface
   // pointer so we don't have to retrieve it from the dispatcher each time.
   // In the host, this value is always NULL.
   const PPP_InputEvent* ppp_input_event_impl_;
 
   DISALLOW_COPY_AND_ASSIGN(PPP_InputEvent_Proxy);
 };
 
 }  // namespace proxy
 }  // namespace ppapi
 
 #endif  // PPAPI_PROXY_PPP_INPUT_EVENT_PROXY_H_