Replace more ObserverList with base::ObserverList.

components/invalidation/ticl_settings_provider.h

 // Copyright 2014 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 COMPONENTS_INVALIDATION_TICL_SETTINGS_PROVIDER_H_
 #define COMPONENTS_INVALIDATION_TICL_SETTINGS_PROVIDER_H_
 
 #include "base/macros.h"
 #include "base/observer_list.h"
 
@@ skipping 16 matching lines @@
 
   virtual bool UseGCMChannel() const = 0;
 
   void AddObserver(Observer* observer);
   void RemoveObserver(Observer* observer);
 
  protected:
   void FireOnUseGCMChannelChanged();
 
  private:
-  ObserverList<Observer, true> observers_;
+  base::ObserverList<Observer, true> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(TiclSettingsProvider);
 };
 
 }  // namespace invalidation
 
 #endif  // COMPONENTS_INVALIDATION_TICL_SETTINGS_PROVIDER_H_