Move Singleton and related structs to namespace base

extensions/browser/extension_message_filter.cc

 // 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.
 
 #include "extensions/browser/extension_message_filter.h"
 
 #include "base/memory/singleton.h"
 #include "components/crx_file/id_util.h"
 #include "components/keyed_service/content/browser_context_keyed_service_shutdown_notifier_factory.h"
 #include "content/public/browser/browser_thread.h"
@@ skipping 14 matching lines @@
 using content::RenderProcessHost;
 
 namespace extensions {
 
 namespace {
 
 class ShutdownNotifierFactory
     : public BrowserContextKeyedServiceShutdownNotifierFactory {
  public:
   static ShutdownNotifierFactory* GetInstance() {
-    return Singleton<ShutdownNotifierFactory>::get();
+    return base::Singleton<ShutdownNotifierFactory>::get();
   }
 
  private:
-  friend struct DefaultSingletonTraits<ShutdownNotifierFactory>;
+  friend struct base::DefaultSingletonTraits<ShutdownNotifierFactory>;
 
   ShutdownNotifierFactory()
       : BrowserContextKeyedServiceShutdownNotifierFactory(
             "ExtensionMessageFilter") {
     DependsOn(EventRouterFactory::GetInstance());
     DependsOn(ProcessManagerFactory::GetInstance());
   }
   ~ShutdownNotifierFactory() override {}
 
   DISALLOW_COPY_AND_ASSIGN(ShutdownNotifierFactory);
@@ skipping 261 matching lines @@
   // The extension has no background page, so there is nothing to wake.
   SendWakeEventPageResponse(request_id, false);
 }
 
 void ExtensionMessageFilter::SendWakeEventPageResponse(int request_id,
                                                        bool success) {
   Send(new ExtensionMsg_WakeEventPageResponse(request_id, success));
 }
 
 }  // namespace extensions