Makes a couple of tests reset state appropriately

chrome/browser/sync/sync_error_notifier_ash_unittest.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 "chrome/browser/sync/sync_error_notifier_ash.h"
 
 #include "ash/test/ash_test_base.h"
 #include "base/memory/scoped_ptr.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/notifications/notification.h"
@@ skipping 90 matching lines @@
     profile_ = profile_manager_->CreateTestingProfile(kTestAccountId);
 
     TestingBrowserProcess::GetGlobal();
     AshTestBase::SetUp();
 
     // Set up a desktop screen for Windows to hold native widgets, used when
     // adding desktop widgets (i.e., message center notifications).
 #if defined(OS_WIN)
     test_screen_.reset(aura::TestScreen::Create(gfx::Size()));
     gfx::Screen::SetScreenInstance(gfx::SCREEN_TYPE_NATIVE, test_screen_.get());
-    gfx::Screen::SetScreenTypeDelegate(new ScreenTypeDelegateDesktop);
+    gfx::Screen::SetScreenTypeDelegate(&screen_type_delegate_);
 #endif
 
     service_.reset(new NiceMock<ProfileSyncServiceMock>(profile_));
 
     FakeLoginUIService* login_ui_service = static_cast<FakeLoginUIService*>(
         LoginUIServiceFactory::GetInstance()->SetTestingFactoryAndUse(
             profile_, BuildMockLoginUIService));
     login_ui_service->SetLoginUI(&login_ui_);
 
     error_controller_.reset(new SyncErrorController(service_.get()));
     error_notifier_.reset(new SyncErrorNotifier(error_controller_.get(),
                                                 profile_));
 
     notification_ui_manager_ = g_browser_process->notification_ui_manager();
   }
 
   void TearDown() override {
     error_notifier_->Shutdown();
     service_.reset();
 #if defined(OS_WIN)
+    gfx::Screen::SetScreenInstance(gfx::SCREEN_TYPE_NATIVE, nullptr);
+    gfx::Screen::SetScreenTypeDelegate(nullptr);
     test_screen_.reset();
 #endif
     profile_manager_.reset();
 
     AshTestBase::TearDown();
   }
 
  protected:
   // Utility function to test that SyncErrorNotifier behaves correctly for the
   // given error condition.
@@ skipping 17 matching lines @@
       ASSERT_TRUE(notification);
       ASSERT_FALSE(notification->title().empty());
       ASSERT_FALSE(notification->title().empty());
       ASSERT_EQ((size_t)1, notification->buttons().size());
     } else {
       ASSERT_FALSE(notification);
     }
   }
 
 #if defined(OS_WIN)
+  ScreenTypeDelegateDesktop screen_type_delegate_;
   scoped_ptr<gfx::Screen> test_screen_;
 #endif
   scoped_ptr<TestingProfileManager> profile_manager_;
   scoped_ptr<SyncErrorController> error_controller_;
   scoped_ptr<SyncErrorNotifier> error_notifier_;
   scoped_ptr<NiceMock<ProfileSyncServiceMock> > service_;
   TestingProfile* profile_;
   FakeLoginUI login_ui_;
   NotificationUIManager* notification_ui_manager_;
 
@@ skipping 50 matching lines @@
     SCOPED_TRACE("Not expecting notification since sync setup is incomplete");
     VerifySyncErrorNotifierResult(
         GoogleServiceAuthError::INVALID_GAIA_CREDENTIALS,
         false /* not signed in */,
         false /* no error */);
   }
 }
 
 }  // namespace test
 }  // namespace ash