Refactor menu controller to isolate aura dependency.

ui/views/controls/menu/menu_message_loop_mac.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 UI_VIEWS_CONTROLS_MENU_MENU_MESSAGE_LOOP_MAC_H_
+#define UI_VIEWS_CONTROLS_MENU_MENU_MESSAGE_LOOP_MAC_H_
+
+#include "base/compiler_specific.h"
+#include "ui/views/controls/menu/menu_message_loop.h"
+
+namespace views {
+
+class MenuMessageLoopMac : public MenuMessageLoop {
+ public:
+  virtual void Run(MenuController* controller, bool nested_menu) OVERRIDE;
+  virtual bool ShouldQuitNow() const OVERRIDE;
+  virtual void QuitNow() OVERRIDE;
+  virtual void RepostEventToWindow(const ui::LocatedEvent& event,
+                                   gfx::NativeWindow window,
+                                   gfx::Point screen_loc) OVERRIDE;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(MenuMessageLoopAura);
+};
+
+}  // namespace views
+
+#endif  // UI_VIEWS_CONTROLS_MENU_MENU_MESSAGE_LOOP_MAC_H_