Moves TransientWindowClient to ui/aura/client and adds observer

ui/views/test/views_test_helper_aura.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 "ui/views/test/views_test_helper_aura.h"
 
 #include "ui/aura/client/screen_position_client.h"
 #include "ui/aura/test/aura_test_helper.h"
 #include "ui/wm/core/capture_controller.h"
 #include "ui/wm/core/default_activation_client.h"
 #include "ui/wm/core/default_screen_position_client.h"
-#include "ui/wm/core/wm_state.h"
 
 namespace views {
 
 // static
 ViewsTestHelper* ViewsTestHelper::Create(base::MessageLoopForUI* message_loop,
                                          ui::ContextFactory* context_factory) {
   return new ViewsTestHelperAura(message_loop, context_factory);
 }
 
 ViewsTestHelperAura::ViewsTestHelperAura(base::MessageLoopForUI* message_loop,
                                          ui::ContextFactory* context_factory)
     : context_factory_(context_factory) {
   aura_test_helper_.reset(new aura::test::AuraTestHelper(message_loop));
 }
 
 ViewsTestHelperAura::~ViewsTestHelperAura() {
 }
 
 void ViewsTestHelperAura::SetUp() {
   aura_test_helper_->SetUp(context_factory_);
   gfx::NativeWindow root_window = GetContext();
   new wm::DefaultActivationClient(root_window);
-  wm_state_.reset(new wm::WMState);
 
   if (!aura::client::GetScreenPositionClient(root_window)) {
     screen_position_client_.reset(new wm::DefaultScreenPositionClient);
     aura::client::SetScreenPositionClient(root_window,
                                           screen_position_client_.get());
   }
 }
 
 void ViewsTestHelperAura::TearDown() {
   // Ensure all Widgets (and windows) are closed in unit tests. This is done
   // automatically when the RootWindow is torn down, but is an error on
   // platforms that must ensure no Compositors are alive when the ContextFactory
   // is torn down.
   // So, although it's optional, check the root window to detect failures before
   // they hit the CQ on other platforms.
   DCHECK(aura_test_helper_->root_window()->children().empty())
       << "Not all windows were closed.";
 
   if (screen_position_client_.get() ==
       aura::client::GetScreenPositionClient(GetContext()))
     aura::client::SetScreenPositionClient(GetContext(), nullptr);
 
   aura_test_helper_->TearDown();
-  wm_state_.reset();
   CHECK(!wm::ScopedCaptureClient::IsActive());
 }
 
 gfx::NativeWindow ViewsTestHelperAura::GetContext() {
   return aura_test_helper_->root_window();
 }
 
 }  // namespace views