Don't check ash accelerators in browser with mash.

chrome/browser/ui/ash/ash_util.cc

 // 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 "chrome/browser/ui/ash/ash_util.h"
 
 #include "ash/accelerators/accelerator_controller.h"
 #include "ash/shell.h"
 #include "build/build_config.h"
 #include "chrome/browser/ui/ash/ash_init.h"
@@ skipping 41 matching lines @@
   }
 
   return false;
 }
 
 bool IsNativeWindowInAsh(gfx::NativeWindow native_window) {
   return IsNativeViewInAsh(native_window);
 }
 
 bool IsAcceleratorDeprecated(const ui::Accelerator& accelerator) {
+  // When running in mash the browser doesn't handle ash accelerators.
+  if (chrome::IsRunningInMash())
+    return false;
+
   ash::AcceleratorController* controller =
       ash::Shell::GetInstance()->accelerator_controller();
   return controller->IsDeprecated(accelerator);
 }
 
 }  // namespace chrome