Move Singleton and related structs to namespace base

extensions/browser/guest_view/web_view/web_view_renderer_state.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 "content/public/browser/browser_thread.h"
 #include "extensions/browser/guest_view/web_view/web_view_renderer_state.h"
 
 using content::BrowserThread;
 
 namespace extensions {
 
 WebViewRendererState::WebViewInfo::WebViewInfo() {
 }
 
 WebViewRendererState::WebViewInfo::~WebViewInfo() {
 }
 
 // static
 WebViewRendererState* WebViewRendererState::GetInstance() {
-  return Singleton<WebViewRendererState>::get();
+  return base::Singleton<WebViewRendererState>::get();
 }
 
 WebViewRendererState::WebViewRendererState() {
 }
 
 WebViewRendererState::~WebViewRendererState() {
 }
 
 bool WebViewRendererState::IsGuest(int render_process_id) const {
   base::AutoLock auto_lock(web_view_partition_id_map_lock_);
@@ skipping 112 matching lines @@
     if (info.embedder_process_id == embedder_process_id &&
         info.instance_id == view_instance_id) {
       for (int id : script_ids)
         info.content_script_ids.erase(id);
       return;
     }
   }
 }
 
 }  // namespace extensions