Replace JSON (de)serialization of extension messages with direct Value pickling.

chrome/renderer/extensions/dispatcher.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 CHROME_RENDERER_EXTENSIONS_DISPATCHER_H_
 #define CHROME_RENDERER_EXTENSIONS_DISPATCHER_H_
 
 #include <map>
 #include <set>
 #include <string>
@@ skipping 133 matching lines @@
 
   void OnSetChannel(int channel);
   void OnMessageInvoke(const std::string& extension_id,
                        const std::string& function_name,
                        const base::ListValue& args,
                        bool user_gesture);
   void OnDispatchOnConnect(int target_port_id,
                            const std::string& channel_name,
                            const base::DictionaryValue& source_tab,
                            const ExtensionMsg_ExternalConnectionInfo& info);
-  void OnDeliverMessage(int target_port_id, const std::string& message);
+  void OnDeliverMessage(int target_port_id, const base::ListValue& message);
   void OnDispatchOnDisconnect(int port_id, const std::string& error_message);
   void OnSetFunctionNames(const std::vector<std::string>& names);
   void OnLoaded(
       const std::vector<ExtensionMsg_Loaded_Params>& loaded_extensions);
   void OnLoadedInternal(scoped_refptr<const Extension> extension);
   void OnUnloaded(const std::string& id);
   void OnSetScriptingWhitelist(
       const Extension::ScriptingWhitelist& extension_ids);
   void OnPageActionsUpdated(const std::string& extension_id,
       const std::vector<std::string>& page_actions);
@@ skipping 110 matching lines @@
 
   // Sends API requests to the extension host.
   scoped_ptr<RequestSender> request_sender_;
 
   DISALLOW_COPY_AND_ASSIGN(Dispatcher);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_RENDERER_EXTENSIONS_DISPATCHER_H_