Move Singleton and related structs to namespace base

components/variations/net/variations_http_header_provider.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 "components/variations/net/variations_http_header_provider.h"
 
 #include <set>
 #include <string>
 #include <vector>
 
@@ skipping 26 matching lines @@
   ".gstatic.com",
   ".ytimg.com",
 };
 
 const char kChromeUMAEnabled[] = "X-Chrome-UMA-Enabled";
 const char kClientData[] = "X-Client-Data";
 
 }  // namespace
 
 VariationsHttpHeaderProvider* VariationsHttpHeaderProvider::GetInstance() {
-  return Singleton<VariationsHttpHeaderProvider>::get();
+  return base::Singleton<VariationsHttpHeaderProvider>::get();
 }
 
 void VariationsHttpHeaderProvider::AppendHeaders(
     const GURL& url,
     bool incognito,
     bool uma_enabled,
     net::HttpRequestHeaders* headers) {
   // Note the criteria for attaching client experiment headers:
   // 1. We only transmit to Google owned domains which can evaluate experiments.
   //    1a. These include hosts which have a standard postfix such as:
@@ skipping 224 matching lines @@
     if (base::EndsWith(host, kSuffixesToSetHeadersFor[i],
                        base::CompareCase::INSENSITIVE_ASCII))
       return true;
   }
 
   return google_util::IsYoutubeDomainUrl(url, google_util::ALLOW_SUBDOMAIN,
                                          google_util::ALLOW_NON_STANDARD_PORTS);
 }
 
 }  // namespace variations