Modify extension request IPC messages to pass a ListValue instead of a string.

chrome/browser/dom_ui/dom_ui.h

 // Copyright (c) 2009 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_BROWSER_DOM_UI_DOM_UI_H_
 #define CHROME_BROWSER_DOM_UI_DOM_UI_H_
 
 #include <map>
 #include <string>
 #include <vector>
@@ skipping 23 matching lines @@
   // RenderViewHostManager will reuse RenderView instances. In those cases,
   // RenderViewReused will be called instead.
   virtual void RenderViewCreated(RenderViewHost* render_view_host) {}
 
   // Called by RenderViewHostManager when a RenderView is reused to display a
   // page.
   virtual void RenderViewReused(RenderViewHost* render_view_host) {}
 
   // Called from TabContents.
   virtual void ProcessDOMUIMessage(const std::string& message,
-                                   const std::string& content,
+                                   const Value* content,
                                    int request_id,
                                    bool has_callback);
 
   // Used by DOMMessageHandlers.
   typedef Callback1<const Value*>::Type MessageCallback;
   void RegisterMessageCallback(const std::string& message,
                                MessageCallback* callback);
 
   // Returns true if the favicon should be hidden for the current tab.
   bool hide_favicon() const {
@@ skipping 120 matching lines @@
   // Extract a string value from a Value.
   std::wstring ExtractStringValue(const Value* value);
 
   DOMUI* dom_ui_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(DOMMessageHandler);
 };
 
 #endif  // CHROME_BROWSER_DOM_UI_DOM_UI_H_