[mus+ash] Removes WmWindow from ash/accelerators

ash/accelerators/accelerator_delegate.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 "ash/accelerators/accelerator_delegate.h"
 
 #include "ash/accelerators/accelerator_router.h"
-#include "ash/wm_window.h"
 #include "ui/aura/window.h"
 #include "ui/events/event.h"
 
 namespace ash {
 
 AcceleratorDelegate::AcceleratorDelegate() : router_(new AcceleratorRouter) {}
 
 AcceleratorDelegate::~AcceleratorDelegate() {}
 
 bool AcceleratorDelegate::ProcessAccelerator(
     const ui::KeyEvent& key_event,
     const ui::Accelerator& accelerator) {
   return router_->ProcessAccelerator(
-      WmWindow::Get(static_cast<aura::Window*>(key_event.target())), key_event,
-      accelerator);
+      static_cast<aura::Window*>(key_event.target()), key_event, accelerator);
 }
 
 }  // namespace ash