Initialize the message center as part of the testing browser process

ash/test/ash_test_helper.cc

Index: ash/test/ash_test_helper.cc
diff --git a/ash/test/ash_test_helper.cc b/ash/test/ash_test_helper.cc
index e92ea0db55093922a9a53aba87ed40150de744e4..227dfddacb0d7e3bf1430326875a5f9cdbebfbe1 100644
--- a/ash/test/ash_test_helper.cc
+++ b/ash/test/ash_test_helper.cc
@@ -32,7 +32,6 @@
 #include "ui/compositor/test/context_factories_for_test.h"
 #include "ui/display/manager/managed_display_info.h"
 #include "ui/display/test/display_manager_test_api.h"
-#include "ui/message_center/message_center.h"
 #include "ui/wm/core/capture_controller.h"
 #include "ui/wm/core/cursor_manager.h"
 #include "ui/wm/core/wm_state.h"
@@ -91,10 +90,6 @@ void AshTestHelper::SetUp(bool start_session,
   if (!test_shell_delegate_)
     test_shell_delegate_ = new TestShellDelegate;
 
-  // Creates MessageCenter since g_browser_process is not created in AshTestBase
-  // tests.
-  message_center::MessageCenter::Initialize();
-
 #if defined(OS_CHROMEOS)
   // Create DBusThreadManager for testing.
   if (!chromeos::DBusThreadManager::IsInitialized()) {
@@ -169,9 +164,6 @@ void AshTestHelper::TearDown() {
 
   test_screenshot_delegate_ = NULL;
 
-  // Remove global message center state.
-  message_center::MessageCenter::Shutdown();
-
 #if defined(OS_CHROMEOS)
   chromeos::CrasAudioHandler::Shutdown();
   if (bluez_dbus_manager_initialized_) {