Cleanup: Remove unneeded forward declarations in ppapi.

ppapi/proxy/ppp_instance_proxy.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 PPAPI_PROXY_PPP_INSTANCE_PROXY_H_
 #define PPAPI_PROXY_PPP_INSTANCE_PROXY_H_
 
 #include <string>
 #include <vector>
 
 #include "base/memory/scoped_ptr.h"
 #include "ppapi/c/pp_instance.h"
 #include "ppapi/c/pp_resource.h"
 #include "ppapi/c/pp_var.h"
 #include "ppapi/proxy/interface_proxy.h"
 #include "ppapi/shared_impl/host_resource.h"
 #include "ppapi/shared_impl/ppp_instance_combined.h"
 
 struct PP_Rect;
 
 namespace ppapi {
 namespace proxy {
 
-class SerializedVarReturnValue;
-
 class PPP_Instance_Proxy : public InterfaceProxy {
  public:
-  PPP_Instance_Proxy(Dispatcher* dispatcher);
+  explicit PPP_Instance_Proxy(Dispatcher* dispatcher);
   virtual ~PPP_Instance_Proxy();
 
   // Return the info for the 1.0 (latest, canonical) version of the interface.
   static const Info* GetInfo1_0();
 
   PPP_Instance_Combined* ppp_instance_target() const {
     return combined_interface_.get();
   }
 
   // InterfaceProxy implementation.
@@ skipping 15 matching lines @@
   void OnMsgHandleDocumentLoad(PP_Instance instance,
                                const HostResource& url_loader,
                                PP_Bool* result);
   scoped_ptr<PPP_Instance_Combined> combined_interface_;
 };
 
 }  // namespace proxy
 }  // namespace ppapi
 
 #endif  // PPAPI_PROXY_PPP_INSTANCE_PROXY_H_