Refactor menu controller to isolate aura dependency.

ui/views/controls/menu/menu_message_loop_mac.cc

+// 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.
+
+#include "ui/views/controls/menu/menu_message_loop_mac.h"
+
+#include "base/message_loop/message_loop.h"
+#include "base/run_loop.h"
+
+namespace views {
+
+// static
+MenuMessageLoop* MenuMessageLoop::Create() {
+  return new MenuMessageLoopMac;
+}
+
+MenuMessageLoopMac::MenuMessageLoopMac()
+    : message_loop_depth_(0) {
+}
+
+MenuMessageLoopMac::~MenuMessageLoopMac() {}
+
+void MenuMessageLoopMac::RepostEventToWindow(const ui::LocatedEvent& event,
+                                             gfx::NativeWindow window,
+                                             gfx::Point screen_loc) OVERRIDE;
+  NOTIMPLEMENTED();
+}
+
+void MenuMessageLoopMac::Run(MenuController* controller,
+                             Widget* owner,
+                             bool nested_menu) {
+  message_loop_depth_++;
+  DCHECK_LE(mesage_loop_depth_, 2);
+
+  base::MessageLoopForUI* loop = base::MessageLoopForUI::current();
+  base::MessageLoop::ScopedNestableTaskAllower allow(loop);
+  base::RunLoop run_loop;
+  run_loop.Run();
+
+  message_loop_depth_--;
+}
+
+bool MenuMessageLoopMac::ShouldQuitNow() const {
+  return true;
+}
+
+void MenuMessageLoopMac::QuitNow() {
+  base::MessageLoop::current()->QuitNow();
+}
+
+int MenuMessageLoopMac::message_loop_depth() const {
+  return message_loop_depth_;
+}
+
+}  // namespace views