Moves handful of files to ash/wm/common

ash/wm/window_state_aura.cc

 // 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.
 
 #include "ash/wm/window_state_aura.h"
 
 #include "ash/wm/aura/wm_window_aura.h"
+#include "ash/wm/common/window_state.h"
 #include "ash/wm/window_properties.h"
-#include "ash/wm/window_state.h"
 #include "ash/wm/window_util.h"
 #include "ui/aura/window.h"
 
 namespace ash {
 namespace wm {
 
 WindowState* GetActiveWindowState() {
   aura::Window* active = GetActiveWindow();
   return active ? GetWindowState(active) : nullptr;
 }
 
 WindowState* GetWindowState(aura::Window* window) {
   if (!window)
     return nullptr;
   WindowState* settings = window->GetProperty(kWindowStateKey);
   if (!settings) {
     settings = new WindowState(WmWindowAura::Get(window));
     window->SetProperty(kWindowStateKey, settings);
   }
   return settings;
 }
 
 const WindowState* GetWindowState(const aura::Window* window) {
   return GetWindowState(const_cast<aura::Window*>(window));
 }
 
 }  // namespace wm
 }  // namespace ash