Initialize the message center as part of the testing browser process

chrome/browser/chromeos/ui/low_disk_notification_unittest.cc

 // Copyright 2016 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/ui/low_disk_notification.h"
 
 #include <stdint.h>
 
 #include "base/threading/platform_thread.h"
 #include "base/time/time.h"
@@ skipping 18 matching lines @@
 namespace chromeos {
 
 class LowDiskNotificationTest : public testing::Test,
                                 public message_center::FakeMessageCenter {
  public:
   LowDiskNotificationTest() {}
 
   void SetUp() override {
     DBusThreadManager::GetSetterForTesting()->SetCryptohomeClient(
         std::unique_ptr<CryptohomeClient>(new FakeCryptohomeClient));
-    message_center::MessageCenter::Initialize();
     low_disk_notification_.reset(new LowDiskNotification());
     low_disk_notification_->SetMessageCenterForTest(this);
     low_disk_notification_->SetNotificationIntervalForTest(
         base::TimeDelta::FromMilliseconds(10));
     notification_count_ = 0;
   }
 
   void TearDown() override {
     low_disk_notification_.reset();
     last_notification_.reset();
-    message_center::MessageCenter::Shutdown();
     DBusThreadManager::Shutdown();
   }
 
   void AddNotification(
       std::unique_ptr<message_center::Notification> notification) override {
     last_notification_ = std::move(notification);
     notification_count_++;
   }
 
  protected:
@@ skipping 36 matching lines @@
 }
 
 TEST_F(LowDiskNotificationTest, MediumNotificationsAreNotShownAfterThrottling) {
   low_disk_notification_->OnLowDiskSpace(kMediumNotification);
   base::PlatformThread::Sleep(base::TimeDelta::FromMilliseconds(15));
   low_disk_notification_->OnLowDiskSpace(kMediumNotification);
   EXPECT_EQ(1, notification_count_);
 }
 
 }  // namespace chromeos