chrome: Cleanup class/struct forward declarations

chrome/browser/chromeos/eol_notification.h

 // 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.
 
 #ifndef CHROME_BROWSER_CHROMEOS_EOL_NOTIFICATION_H_
 #define CHROME_BROWSER_CHROMEOS_EOL_NOTIFICATION_H_
 
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "base/strings/string16.h"
 #include "chrome/browser/profiles/profile.h"
 #include "third_party/cros_system_api/dbus/update_engine/dbus-constants.h"
 
-namespace message_center {
-class MessageCenter;
-}
-
 namespace chromeos {
 
 // EolNotification is created when user logs in. It is
 // used to check current EndOfLife Status of the device,
 // and show notification accordingly.
 class EolNotification final {
  public:
   explicit EolNotification(Profile* profile);
   ~EolNotification();
 
@@ skipping 18 matching lines @@
 
   // Factory of callbacks.
   base::WeakPtrFactory<EolNotification> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(EolNotification);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_EOL_NOTIFICATION_H_