Move Singleton and related structs to namespace base

chrome/browser/upgrade_detector_impl.cc

 // Copyright (c) 2012 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/upgrade_detector_impl.h"
 
 #include <string>
 
 #include "base/bind.h"
 #include "base/build_time.h"
@@ skipping 493 matching lines @@
 }
 
 void UpgradeDetectorImpl::NotifyOnUpgrade() {
   const base::TimeDelta time_passed =
       base::TimeTicks::Now() - upgrade_detected_time_;
   NotifyOnUpgradeWithTimePassed(time_passed);
 }
 
 // static
 UpgradeDetectorImpl* UpgradeDetectorImpl::GetInstance() {
-  return Singleton<UpgradeDetectorImpl>::get();
+  return base::Singleton<UpgradeDetectorImpl>::get();
 }
 
 // static
 UpgradeDetector* UpgradeDetector::GetInstance() {
   return UpgradeDetectorImpl::GetInstance();
 }