Move Singleton and related structs to namespace base

components/sessions/content/content_serialized_navigation_driver.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/sessions/content/content_serialized_navigation_driver.h"
 
 #include "base/memory/singleton.h"
 #include "components/sessions/serialized_navigation_entry.h"
 #include "content/public/common/page_state.h"
 #include "content/public/common/referrer.h"
 #include "content/public/common/url_constants.h"
 
 namespace sessions {
 
 namespace {
 const int kObsoleteReferrerPolicyAlways = 0;
 const int kObsoleteReferrerPolicyDefault = 1;
 const int kObsoleteReferrerPolicyNever = 2;
 const int kObsoleteReferrerPolicyOrigin = 3;
 }  // namespace
 
 // static
 SerializedNavigationDriver* SerializedNavigationDriver::Get() {
   return ContentSerializedNavigationDriver::GetInstance();
 }
 
 // static
 ContentSerializedNavigationDriver*
 ContentSerializedNavigationDriver::GetInstance() {
-  return Singleton<ContentSerializedNavigationDriver,
-      LeakySingletonTraits<ContentSerializedNavigationDriver>>::get();
+  return base::Singleton<
+      ContentSerializedNavigationDriver,
+      base::LeakySingletonTraits<ContentSerializedNavigationDriver>>::get();
 }
 
 ContentSerializedNavigationDriver::ContentSerializedNavigationDriver() {
 }
 
 ContentSerializedNavigationDriver::~ContentSerializedNavigationDriver() {
 }
 
 int ContentSerializedNavigationDriver::GetDefaultReferrerPolicy() const {
   return blink::WebReferrerPolicyDefault;
@@ skipping 83 matching lines @@
 }
 
 std::string ContentSerializedNavigationDriver::StripReferrerFromPageState(
       const std::string& page_state) const {
   return content::PageState::CreateFromEncodedData(page_state)
       .RemoveReferrer()
       .ToEncodedData();
 }
 
 }  // namespace sessions