Move Singleton and related structs to namespace base

extensions/browser/api/socket/app_firewall_hole_manager.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 "extensions/browser/api/socket/app_firewall_hole_manager.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/stl_util.h"
@@ skipping 10 matching lines @@
 
 class AppFirewallHoleManagerFactory : public BrowserContextKeyedServiceFactory {
  public:
   static AppFirewallHoleManager* GetForBrowserContext(BrowserContext* context,
                                                       bool create) {
     return static_cast<AppFirewallHoleManager*>(
         GetInstance()->GetServiceForBrowserContext(context, create));
   }
 
   static AppFirewallHoleManagerFactory* GetInstance() {
-    return Singleton<AppFirewallHoleManagerFactory>::get();
+    return base::Singleton<AppFirewallHoleManagerFactory>::get();
   }
 
   AppFirewallHoleManagerFactory()
       : BrowserContextKeyedServiceFactory(
             "AppFirewallHoleManager",
             BrowserContextDependencyManager::GetInstance()) {
     DependsOn(AppWindowRegistry::Factory::GetInstance());
   }
 
   ~AppFirewallHoleManagerFactory() override {}
@@ skipping 115 matching lines @@
 
 void AppFirewallHoleManager::OnAppWindowShown(AppWindow* app_window,
                                               bool was_hidden) {
   const auto& range = tracked_holes_.equal_range(app_window->extension_id());
   for (auto iter = range.first; iter != range.second; ++iter) {
     iter->second->SetVisible(true);
   }
 }
 
 }  // namespace extensions