mash: Convert FocusCycler to wm common types and move to //ash/common

ash/aura/wm_window_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/aura/wm_window_aura.h"
 
 #include "ash/aura/aura_layout_manager_adapter.h"
 #include "ash/aura/wm_root_window_controller_aura.h"
 #include "ash/aura/wm_shell_aura.h"
 #include "ash/common/ash_constants.h"
@@ skipping 499 matching lines @@
 }
 
 void WmWindowAura::Hide() {
   window_->Hide();
 }
 
 void WmWindowAura::Show() {
   window_->Show();
 }
 
+views::Widget* WmWindowAura::GetInternalWidget() {
+  return views::Widget::GetWidgetForNativeView(window_);
+}
+
 void WmWindowAura::CloseWidget() {
-  DCHECK(views::Widget::GetWidgetForNativeView(window_));
-  views::Widget::GetWidgetForNativeView(window_)->Close();
+  DCHECK(GetInternalWidget());
+  GetInternalWidget()->Close();
 }
 
 bool WmWindowAura::IsFocused() const {
   return window_->HasFocus();
 }
 
 bool WmWindowAura::IsActive() const {
   return wm::IsActiveWindow(window_);
 }
 
@@ skipping 161 matching lines @@
                                               bool visible) {
   FOR_EACH_OBSERVER(WmWindowObserver, observers_,
                     OnWindowVisibilityChanging(this, visible));
 }
 
 void WmWindowAura::OnWindowTitleChanged(aura::Window* window) {
   FOR_EACH_OBSERVER(WmWindowObserver, observers_, OnWindowTitleChanged(this));
 }
 
 }  // namespace ash