Separate out logic to handle different category/group of context menu items from RVContextMenu class

chrome/browser/tab_contents/menu_category_app_mode.h

+// Copyright 2014 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_TAB_CONTENTS_MENU_CATEGORY_APP_MODE_H_
+#define CHROME_BROWSER_TAB_CONTENTS_MENU_CATEGORY_APP_MODE_H_
+
+#include "chrome/browser/tab_contents/menu_category_base.h"
+
+class MenuCategoryAppMode : public MenuCategoryBase {
+ public:
+  virtual ~MenuCategoryAppMode();
+
+ protected:
+  MenuCategoryAppMode(
+      content::RenderFrameHost* render_frame_host,
+      const content::ContextMenuParams& params);
+
+  // MenuCategoryBase overrides.
+  virtual bool IsCategoryEnabled(int category) OVERRIDE;
+
+ private:
+  friend class MenuCategoryFactory;
+
+  DISALLOW_COPY_AND_ASSIGN(MenuCategoryAppMode);
+};
+
+#endif  // CHROME_BROWSER_TAB_CONTENTS_MENU_CATEGORY_APP_MODE_H_