Allow Widget to pass accelerator handling to its parent.

ui/views/cocoa/native_widget_mac_accelerator_handler.h

Index: ui/views/cocoa/native_widget_mac_accelerator_handler.h
diff --git a/ui/views/cocoa/native_widget_mac_accelerator_handler.h b/ui/views/cocoa/native_widget_mac_accelerator_handler.h
new file mode 100644
index 0000000000000000000000000000000000000000..66a446adc94f8303c9da0b1ec62e662d7b91f575
--- /dev/null
+++ b/ui/views/cocoa/native_widget_mac_accelerator_handler.h
@@ -0,0 +1,19 @@
+// Copyright 2016 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_COCOA_NATIVE_WIDGET_MAC_ACCELERATOR_HANDLER_H_
+#define UI_VIEWS_COCOA_NATIVE_WIDGET_MAC_ACCELERATOR_HANDLER_H_
+
+#include "ui/base/cocoa/user_interface_item_command_handler.h"
+
+@class NativeWidgetMacNSWindow;
+
+@interface NativeWidgetMacAcceleratorHandler
+    : NSObject<UserInterfaceItemCommandHandler>
+
+- (instancetype)initWithParentWindow:(NSWindow*)parent;
+
+@end
+
+#endif  // UI_VIEWS_COCOA_NATIVE_WIDGET_MAC_ACCELERATOR_HANDLER_H_