Refactor menu controller to isolate aura dependency.

ui/views/controls/menu/menu_message_loop.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_H_
+#define UI_VIEWS_CONTROLS_MENU_MENU_MESSAGE_LOOP_H_
+
+#include "ui/gfx/native_widget_types.h"
+
+namespace gfx {
+class Point;
+}
+
+namespace ui {
+class LocatedEvent;
+}
+
+namespace views {
+
+class MenuController;
+class Widget;
+
+// Interface used by MenuController to run a nested message loop while
+// showing a menu, allowing for platform specific implementations.
+class MenuMessageLoop {
+ public:
+  virtual ~MenuMessageLoop() {}
+
+  // Create a platform specific instance.
+  static MenuMessageLoop* Create();
+
+  // Runs the platform specific bits of the message loop. If |nested_menu| is
+  // true we're being asked to run a menu from within a menu (eg a context
+  // menu).
+  virtual void Run(MenuController*, Widget* owner, bool nested_menu) = 0;
+
+  virtual bool ShouldQuitNow() const = 0;
+  virtual void QuitNow() = 0;
+  virtual void RepostEventToWindow(const ui::LocatedEvent& event,
+                                   gfx::NativeWindow window,
+                                   gfx::Point screen_loc) = 0;
+};
+
+}  // namespace views
+
+#endif  // UI_VIEWS_CONTROLS_MENU_MENU_MESSAGE_LOOP_H_