added CTRL+Click and SHIFT+Click handler for context menu, Back and Forward.

ui/base/models/menu_model.cc

 // 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.
 
 #include "ui/base/models/menu_model.h"
 
 namespace ui {
 
 int MenuModel::GetFirstItemIndex(gfx::NativeMenu native_menu) const {
   return 0;
@@ skipping 21 matching lines @@
       return true;
     }
   }
   return false;
 }
 
 const gfx::Font* MenuModel::GetLabelFontAt(int index) const {
   return NULL;
 }
 
-// Default implementation ignores the disposition.
-void MenuModel::ActivatedAtWithDisposition(int index, int disposition) {
+// Default implementation ignores the flags
+void MenuModel::ActivatedAtWithFlags(int index, int flags) {
   ActivatedAt(index);
 }
 
 }  // namespace ui