Adds WmWindow and converts WindowState to use it

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_controller.h"
 #include "ash/shell.h"
 #include "ash/wm/window_state.h"
+#include "ash/wm/window_state_aura.h"
 #include "ui/base/accelerators/accelerator.h"
 #include "ui/events/event.h"
 #include "ui/wm/core/window_util.h"
 
 namespace ash {
 namespace {}  // namespace
 
 AcceleratorDelegate::AcceleratorDelegate() {
 }
 AcceleratorDelegate::~AcceleratorDelegate() {
@@ skipping 62 matching lines @@
 
   // Handle preferred accelerators (such as ALT-TAB) before sending
   // to the target.
   if (shell->accelerator_controller()->IsPreferred(accelerator))
     return true;
 
   return shell->GetAppListTargetVisibility();
 }
 
 }  // namespace ash