Cleanup: Remove unneeded forward declarations in webkit/plugins/.

webkit/plugins/ppapi/ppapi_plugin_instance.h

 // Copyright (c) 2011 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 WEBKIT_PLUGINS_PPAPI_PPAPI_PLUGIN_INSTANCE_H_
 #define WEBKIT_PLUGINS_PPAPI_PPAPI_PLUGIN_INSTANCE_H_
 
 #include <map>
 #include <set>
 #include <string>
@@ skipping 49 matching lines @@
 namespace ppapi {
 struct PPP_Instance_Combined;
 class Resource;
 }
 
 namespace webkit {
 namespace ppapi {
 
 class FullscreenContainer;
 class MessageChannel;
-class ObjectVar;
 class PluginDelegate;
 class PluginModule;
 class PluginObject;
 class PPB_Graphics2D_Impl;
 class PPB_Graphics3D_Impl;
 class PPB_ImageData_Impl;
 class PPB_Surface3D_Impl;
 class PPB_URLLoader_Impl;
 class PPB_URLRequestInfo_Impl;
 
@@ skipping 526 matching lines @@
 
   PP_CompletionCallback lock_mouse_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(PluginInstance);
 };
 
 }  // namespace ppapi
 }  // namespace webkit
 
 #endif  // WEBKIT_PLUGINS_PPAPI_PPAPI_PLUGIN_INSTANCE_H_