Move platform_thread to base/threading and put in the base namespace. I left ...

chrome/profile_import/profile_import_main.cc

 // Copyright (c) 2009 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 "base/command_line.h"
 #include "base/message_loop.h"
 #include "base/string_util.h"
+#include "base/threading/platform_thread.h"
 #include "chrome/common/child_process.h"
 #include "chrome/common/chrome_constants.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/logging_chrome.h"
 #include "chrome/common/main_function_params.h"
 #include "chrome/profile_import/profile_import_thread.h"
 
 // Mainline routine for running as the profile import process.
 int ProfileImportMain(const MainFunctionParams& parameters) {
   // The main message loop of the profile import process.
   MessageLoop main_message_loop;
-  PlatformThread::SetName("CrProfileImportMain");
+  base::PlatformThread::SetName("CrProfileImportMain");
 
   ChildProcess profile_import_process;
   profile_import_process.set_main_thread(new ProfileImportThread());
 
   MessageLoop::current()->Run();
 
   return 0;
 }