Fixes issue with accelerators when a menu is open

ash/accelerators/accelerator_dispatcher_win.cc

Index: ash/accelerators/accelerator_dispatcher_win.cc
diff --git a/ash/accelerators/accelerator_dispatcher_win.cc b/ash/accelerators/accelerator_dispatcher_win.cc
new file mode 100644
index 0000000000000000000000000000000000000000..46822755c8e61474567ad0c9de68b750566c7cb6
--- /dev/null
+++ b/ash/accelerators/accelerator_dispatcher_win.cc
@@ -0,0 +1,39 @@
+// 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/accelerator_dispatcher.h"
+
+#include "ash/accelerators/accelerator_controller.h"
+#include "ash/shell.h"
+#include "ui/aura/event.h"
+#include "ui/aura/root_window.h"
+#include "ui/base/accelerators/accelerator.h"
+
+namespace ash {
+
+namespace {
+
+const int kModifierMask = (ui::EF_SHIFT_DOWN |
+                           ui::EF_CONTROL_DOWN |
+                           ui::EF_ALT_DOWN);
+}  // namespace
+
+bool AcceleratorDispatcher::Dispatch(const MSG& msg) {
+  ash::Shell* shell = ash::Shell::GetInstance();
+  if (shell->IsScreenLocked())
+    return aura::RootWindow::GetInstance()->GetDispatcher()->Dispatch(msg);
+
+  if(msg.message == WM_KEYDOWN || msg.message == WM_SYSKEYDOWN) {
+    ash::AcceleratorController* accelerator_controller =
+        shell->accelerator_controller();
+    ui::Accelerator accelerator(ui::KeyboardCodeFromNative(msg),
+        ui::EventFlagsFromNative(msg) & kModifierMask);
+    if (accelerator_controller && accelerator_controller->Process(accelerator))
+      return true;
+  }
+
+  return nested_dispatcher_->Dispatch(msg);
+}
+
+}  // namespace ash