Fixes issue with accelerators when a menu is open

ash/accelerators/nested_dispatcher_controller.cc

Index: ash/accelerators/nested_dispatcher_controller.cc
diff --git a/ash/accelerators/nested_dispatcher_controller.cc b/ash/accelerators/nested_dispatcher_controller.cc
new file mode 100644
index 0000000000000000000000000000000000000000..747a2cec509ecfcf2a6218ec0f0c830c15d7a1a3
--- /dev/null
+++ b/ash/accelerators/nested_dispatcher_controller.cc
@@ -0,0 +1,28 @@
+// Copyright (c) 2012 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 "ash/accelerators/nested_dispatcher_controller.h"
+
+#include "ash/accelerators/accelerator_dispatcher.h"
+
+namespace ash {
+
+NestedDispatcherController::NestedDispatcherController() {
+  aura::client::SetDispatcherClient(this);
+}
+
+void NestedDispatcherController::RunWithDispatcher(
+    MessageLoop::Dispatcher* nested_dispatcher,
+    bool nestable_tasks_allowed) {
+  MessageLoopForUI* loop = MessageLoopForUI::current();
+  bool did_allow_task_nesting = loop->NestableTasksAllowed();
+  loop->SetNestableTasksAllowed(nestable_tasks_allowed);
+
+  AcceleratorDispatcher dispatcher(nested_dispatcher);
+
+  loop->RunWithDispatcher(&dispatcher);
+  loop->SetNestableTasksAllowed(did_allow_task_nesting);
+}
+
+}  // namespace ash