Fix up some reference counting when WebPluginImpl::scriptableObject is called.

webkit/plugins/ppapi/message_channel.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_MESSAGE_CHANNEL_H_
 #define WEBKIT_PLUGINS_PPAPI_MESSAGE_CHANNEL_H_
 
 #include "base/task.h"
 #include "third_party/npapi/bindings/npruntime.h"
 #include "webkit/plugins/ppapi/resource.h"
@@ skipping 41 matching lines @@
   // channel's instance.
   void PostMessageToNative(PP_Var message_data);
 
   // Return the NPObject* to which we should forward any calls which aren't
   // related to postMessage.  Note that this can be NULL;  it only gets set if
   // there is a scriptable 'InstanceObject' associated with this channel's
   // instance.
   NPObject* passthrough_object() {
     return passthrough_object_;
   }
-  void set_passthrough_object(NPObject* passthrough) {
-    passthrough_object_ = passthrough;
-  }
+  void SetPassthroughObject(NPObject* passthrough);
 
   NPObject* np_object() { return np_object_; }
 
   PluginInstance* instance() {
     return instance_;
   }
 
  private:
   PluginInstance* instance_;
 
@@ skipping 27 matching lines @@
   ScopedRunnableMethodFactory<MessageChannel> method_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(MessageChannel);
 };
 
 }  // namespace ppapi
 }  // namespace webkit
 
 #endif  // WEBKIT_PLUGINS_PPAPI_MESSAGE_CHANNEL_H_