Remove duplicate NotificationObserver mock.

chrome/test/mock_notification_observer.h

Index: chrome/test/mock_notification_observer.h
diff --git a/chrome/test/mock_notification_observer.h b/chrome/test/mock_notification_observer.h
deleted file mode 100644
index 71a7d5587979454e9d5adbed3522410ab68aaaac..0000000000000000000000000000000000000000
--- a/chrome/test/mock_notification_observer.h
+++ /dev/null
@@ -1,22 +0,0 @@
-// Copyright (c) 2010 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_TEST_MOCK_NOTIFICATION_OBSERVER_H_
-#define CHROME_TEST_MOCK_NOTIFICATION_OBSERVER_H_
-#pragma once
-
-#include "chrome/common/notification_observer.h"
-#include "chrome/common/notification_details.h"
-#include "chrome/common/notification_service.h"
-#include "chrome/common/notification_type.h"
-#include "testing/gmock/include/gmock/gmock.h"
-
-class MockNotificationObserver : public NotificationObserver {
- public:
-  MOCK_METHOD3(Observe, void(NotificationType,
-                             const NotificationSource&,
-                             const NotificationDetails&));
-};
-
-#endif  // CHROME_TEST_MOCK_NOTIFICATION_OBSERVER_H_