Move extension messages to their own file and add a RenderViewObserver to start moving the extens...

chrome/renderer/extensions/extension_helper.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 CHROME_RENDERER_EXTENSIONS_EXTENSION_HELPER_H_
+#define CHROME_RENDERER_EXTENSIONS_EXTENSION_HELPER_H_
+#pragma once
+
+#include "content/renderer/render_view_observer.h"
+
+class GURL;
+class ListValue;
+
+// Filters extension related messages sent to RenderViews.
+class ExtensionHelper : public RenderViewObserver {
+ public:
+  explicit ExtensionHelper(RenderView* render_view);
+  virtual ~ExtensionHelper();
+
+ private:
+  // RenderViewObserver implementation.
+  virtual bool OnMessageReceived(const IPC::Message& message);
+
+  void OnExtensionResponse(int request_id, bool success,
+                           const std::string& response,
+                           const std::string& error);
+  void OnExtensionMessageInvoke(const std::string& extension_id,
+                                const std::string& function_name,
+                                const ListValue& args,
+                                const GURL& event_url);
+
+
+  DISALLOW_COPY_AND_ASSIGN(ExtensionHelper);
+};
+
+#endif  // CHROME_RENDERER_EXTENSIONS_EXTENSION_HELPER_H_