Move Singleton and related structs to namespace base

content/browser/zygote_host/zygote_host_impl_linux.cc

 // 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.
 
 #include "content/browser/zygote_host/zygote_host_impl_linux.h"
 
 #include <string.h>
 #include <sys/socket.h>
 #include <sys/stat.h>
 #include <sys/types.h>
@@ skipping 81 matching lines @@
       have_read_sandbox_status_word_(false),
       sandbox_status_(0),
       child_tracking_lock_(),
       list_of_running_zygote_children_(),
       should_teardown_after_last_child_exits_(false) {}
 
 ZygoteHostImpl::~ZygoteHostImpl() { TearDown(); }
 
 // static
 ZygoteHostImpl* ZygoteHostImpl::GetInstance() {
-  return Singleton<ZygoteHostImpl>::get();
+  return base::Singleton<ZygoteHostImpl>::get();
 }
 
 void ZygoteHostImpl::Init(const std::string& sandbox_cmd) {
   DCHECK(!init_);
   init_ = true;
 
   base::FilePath chrome_path;
   CHECK(PathService::Get(base::FILE_EXE, &chrome_path));
   base::CommandLine cmd_line(chrome_path);
 
@@ skipping 480 matching lines @@
   }
 
   if (!sandbox::Credentials::CanCreateProcessInNewUserNS()) {
     return false;
   }
 
   return true;
 }
 
 }  // namespace content