aura: Clean up compositor initialization/destruction.

chrome/test/base/view_event_test_base.cc

Index: chrome/test/base/view_event_test_base.cc
diff --git a/chrome/test/base/view_event_test_base.cc b/chrome/test/base/view_event_test_base.cc
index aabfb25f6148ec5f6617d4717be8e3bbe4e77ee4..e0e04dcb3d904399eb49e7114fe610ab8b07e1ca 100644
--- a/chrome/test/base/view_event_test_base.cc
+++ b/chrome/test/base/view_event_test_base.cc
@@ -20,6 +20,7 @@
 
 #if defined(USE_ASH)
 #include "ash/shell.h"
+#include "ash/test/ash_test_helper.h"
 #include "ash/test/test_session_state_delegate.h"
 #include "ash/test/test_shell_delegate.h"
 #endif
@@ -101,23 +102,14 @@ void ViewEventTestBase::SetUp() {
   // interactive_ui_tests is brought up on that platform.
   gfx::Screen::SetScreenInstance(
       gfx::SCREEN_TYPE_NATIVE, views::CreateDesktopScreen());
-#else
-  // Ash Shell can't just live on its own without a browser process, we need to
-  // also create the message center.
-  message_center::MessageCenter::Initialize();
-#if defined(OS_CHROMEOS)
-  chromeos::CrasAudioHandler::InitializeForTesting();
-#endif
-  ash::test::TestShellDelegate* shell_delegate =
-      new ash::test::TestShellDelegate();
-  ash::Shell::CreateInstance(shell_delegate);
-  shell_delegate->test_session_state_delegate()
-      ->SetActiveUserSessionStarted(true);
-  context = ash::Shell::GetPrimaryRootWindow();
 #endif
+  ash_test_helper_.reset(
+      new ash::test::AshTestHelper(base::MessageLoopForUI::current()));
+  ash_test_helper_->SetUp();
+  context = ash_test_helper_->CurrentContext();
 #elif defined(USE_AURA)
-  // Instead of using the ash shell, use an AuraTestHelper to create and manage
-  // the test screen.
+  // Instead of using the AshTestHelper, use an AuraTestHelper to create and
+  // manage the test screen.
   aura_test_helper_.reset(
       new aura::test::AuraTestHelper(base::MessageLoopForUI::current()));
   aura_test_helper_->SetUp();
@@ -136,21 +128,13 @@ void ViewEventTestBase::TearDown() {
 #endif
     window_ = NULL;
   }
+
 #if defined(USE_ASH)
-#if defined(OS_WIN)
-#else
-  ash::Shell::DeleteInstance();
-#if defined(OS_CHROMEOS)
-  chromeos::CrasAudioHandler::Shutdown();
-#endif
-  // Ash Shell can't just live on its own without a browser process, we need to
-  // also shut down the message center.
-  message_center::MessageCenter::Shutdown();
-  aura::Env::DeleteInstance();
-#endif
+  ash_test_helper_->TearDown();
 #elif defined(USE_AURA)
   aura_test_helper_->TearDown();
 #endif
+
   ui::ShutdownInputMethodForTesting();
 }