Replace more ObserverList with base::ObserverList.

ui/views/win/windows_session_change_observer.cc

 // Copyright 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 "ui/views/win/windows_session_change_observer.h"
 
 #include <wtsapi32.h>
 #pragma comment(lib, "wtsapi32.lib")
 
 #include "base/bind.h"
@@ skipping 81 matching lines @@
     //   1) Destruction due to Singleton Destruction.
     //   2) WM_DESTROY fired by SingletonHwnd.
     // Under both cases we are in shutdown, which means no other worker threads
     // can be running.
     WTSUnRegisterSessionNotification(gfx::SingletonHwnd::GetInstance()->hwnd());
     FOR_EACH_OBSERVER(WindowsSessionChangeObserver,
                       observer_list_,
                       ClearCallback());
   }
 
-  ObserverList<WindowsSessionChangeObserver, true> observer_list_;
+  base::ObserverList<WindowsSessionChangeObserver, true> observer_list_;
   scoped_ptr<gfx::SingletonHwndObserver> singleton_hwnd_observer_;
 
   DISALLOW_COPY_AND_ASSIGN(WtsRegistrationNotificationManager);
 };
 
 WindowsSessionChangeObserver::WindowsSessionChangeObserver(
     const WtsCallback& callback)
     : callback_(callback) {
   DCHECK(!callback_.is_null());
   WtsRegistrationNotificationManager::GetInstance()->AddObserver(this);
 }
 
 WindowsSessionChangeObserver::~WindowsSessionChangeObserver() {
   ClearCallback();
 }
 
 void WindowsSessionChangeObserver::OnSessionChange(WPARAM wparam) {
   callback_.Run(wparam);
 }
 
 void WindowsSessionChangeObserver::ClearCallback() {
   if (!callback_.is_null()) {
     callback_.Reset();
     WtsRegistrationNotificationManager::GetInstance()->RemoveObserver(this);
   }
 }
 
 }  // namespace views