PPAPI: Make blocking completion callbacks work.

ppapi/proxy/ppb_instance_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_PPB_INSTANCE_PROXY_H_
 #define PPAPI_PROXY_PPB_INSTANCE_PROXY_H_
 
 #include "ppapi/c/pp_instance.h"
 #include "ppapi/c/pp_resource.h"
 #include "ppapi/c/pp_time.h"
@@ skipping 67 matching lines @@
   virtual void ZoomChanged(PP_Instance instance, double factor) OVERRIDE;
   virtual void ZoomLimitsChanged(PP_Instance instance,
                                  double minimum_factor,
                                  double maximium_factor) OVERRIDE;
   virtual void PostMessage(PP_Instance instance, PP_Var message) OVERRIDE;
   virtual PP_Bool SetCursor(PP_Instance instance,
                             PP_MouseCursor_Type type,
                             PP_Resource image,
                             const PP_Point* hot_spot) OVERRIDE;
   virtual int32_t LockMouse(PP_Instance instance,
-                            PP_CompletionCallback callback) OVERRIDE;
+                            scoped_refptr<TrackedCallback> callback) OVERRIDE;
   virtual void UnlockMouse(PP_Instance instance) OVERRIDE;
   virtual PP_Bool GetDefaultPrintSettings(
       PP_Instance instance,
       PP_PrintSettings_Dev* print_settings) OVERRIDE;
   virtual void SetTextInputType(PP_Instance instance,
                                 PP_TextInput_Type type) OVERRIDE;
   virtual void UpdateCaretPosition(PP_Instance instance,
                                    const PP_Rect& caret,
                                    const PP_Rect& bounding_box) OVERRIDE;
   virtual void CancelCompositionText(PP_Instance instance) OVERRIDE;
@@ skipping 96 matching lines @@
   void MouseLockCompleteInHost(int32_t result, PP_Instance instance);
 
   pp::CompletionCallbackFactory<PPB_Instance_Proxy,
                                 ProxyNonThreadSafeRefCount> callback_factory_;
 };
 
 }  // namespace proxy
 }  // namespace ppapi
 
 #endif  // PPAPI_PROXY_PPB_INSTANCE_PROXY_H_