[Athena, Cleanup] rename WidnowManager::GetInstance -> ::Get

athena/wm/test/window_manager_impl_test_api.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 "athena/wm/test/window_manager_impl_test_api.h"
 
 #include "athena/wm/window_manager_impl.h"
 
 namespace athena {
 namespace test {
 
 WindowManagerImplTestApi::WindowManagerImplTestApi()
-    : wm_(static_cast<WindowManagerImpl*>(WindowManager::GetInstance())) {
+    : wm_(static_cast<WindowManagerImpl*>(WindowManager::Get())) {
 }
 
 WindowManagerImplTestApi::~WindowManagerImplTestApi() {
 }
 
 athena::WindowListProvider* WindowManagerImplTestApi::GetWindowListProvider() {
   return wm_->window_list_provider_.get();
 }
 
 athena::SplitViewController*
 WindowManagerImplTestApi::GetSplitViewController() {
   return wm_->split_view_controller_.get();
 }
 
 }  // namespace test
 }  // namespace athena