Initialize the message center as part of the testing browser process

chrome/browser/chromeos/status/data_promo_notification_unittest.cc

 // Copyright (c) 2015 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/chromeos/status/data_promo_notification.h"
 
 #include "base/command_line.h"
 #include "base/macros.h"
 #include "base/run_loop.h"
 #include "chrome/browser/chromeos/login/users/fake_chrome_user_manager.h"
@@ skipping 52 matching lines @@
 
   void SetUp() override {
     testing::Test::SetUp();
     base::CommandLine::ForCurrentProcess()->AppendSwitch(
         switches::kEnableDataSaverPrompt);
     DBusThreadManager::Initialize();
     NetworkHandler::Initialize();
     data_promo_notification_.reset(new DataPromoNotification);
     SetupUser();
     SetupNetworkShillState();
-    message_center::MessageCenter::Initialize();
     base::RunLoop().RunUntilIdle();
     network_connect_delegate_.reset(new NetworkConnectTestDelegate);
     chromeos::NetworkConnect::Initialize(network_connect_delegate_.get());
   }
 
   void TearDown() override {
     chromeos::NetworkConnect::Shutdown();
     network_connect_delegate_.reset();
-    message_center::MessageCenter::Shutdown();
     LoginState::Shutdown();
     profile_manager_.reset();
     user_manager_enabler_.reset();
     data_promo_notification_.reset();
     NetworkHandler::Shutdown();
     DBusThreadManager::Shutdown();
     testing::Test::TearDown();
   }
 
  protected:
@@ skipping 66 matching lines @@
 
   chromeos::NetworkConnect::Get()->ConnectToNetworkId(kCellularGuid);
   base::RunLoop().RunUntilIdle();
   // Connecting to cellular network (which here makes it the default network)
   // should trigger the Data Saver notification.
   EXPECT_TRUE(message_center->FindVisibleNotificationById(kNotificationId));
 }
 
 }  // namespace test
 }  // namespace chromeos