Move Singleton and related structs to namespace base

content/browser/browser_url_handler_impl.h

 // 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.
 
 #ifndef CONTENT_BROWSER_BROWSER_URL_HANDLER_IMPL_H_
 #define CONTENT_BROWSER_BROWSER_URL_HANDLER_IMPL_H_
 
 #include <vector>
 #include <utility>
 
@@ skipping 23 matching lines @@
   void FixupURLBeforeRewrite(GURL* url, BrowserContext* browser_context);
 
   // Reverses the rewriting that was done for |original| using the new |url|.
   bool ReverseURLRewrite(GURL* url, const GURL& original,
                          BrowserContext* browser_context);
 
  private:
   // This object is a singleton:
   BrowserURLHandlerImpl();
   ~BrowserURLHandlerImpl() override;
-  friend struct DefaultSingletonTraits<BrowserURLHandlerImpl>;
+  friend struct base::DefaultSingletonTraits<BrowserURLHandlerImpl>;
 
   // A URLHandler to run in a preliminary phase, before rewriting is done.
   URLHandler fixup_handler_;
 
   // The list of known URLHandlers, optionally with reverse-rewriters.
   typedef std::pair<URLHandler, URLHandler> HandlerPair;
   std::vector<HandlerPair> url_handlers_;
 
   FRIEND_TEST_ALL_PREFIXES(BrowserURLHandlerImplTest, BasicRewriteAndReverse);
   FRIEND_TEST_ALL_PREFIXES(BrowserURLHandlerImplTest, NullHandlerReverse);
   FRIEND_TEST_ALL_PREFIXES(BrowserURLHandlerImplTest, ViewSourceReverse);
 
   DISALLOW_COPY_AND_ASSIGN(BrowserURLHandlerImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_BROWSER_URL_HANDLER_IMPL_H_