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

chrome/test/tab_switching/tab_switching_test.cc

 // Copyright (c) 2010 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/environment.h"
 #include "base/file_path.h"
 #include "base/file_util.h"
 #include "base/path_service.h"
-#include "base/platform_thread.h"
 #include "base/scoped_ptr.h"
+#include "base/threading/platform_thread.h"
 #include "base/time.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/app/chrome_command_ids.h"
 #include "chrome/common/chrome_paths.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/env_vars.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/test/automation/tab_proxy.h"
 #include "chrome/test/automation/browser_proxy.h"
 #include "chrome/test/ui/ui_perf_test.h"
@@ skipping 83 matching lines @@
 
       // Open the corresponding log file and collect average from the
       // histogram stats generated for RenderWidgetHost_TabSwitchPaintDuration.
       bool log_has_been_dumped = false;
       std::string contents;
       int max_tries = 20;
       do {
         log_has_been_dumped = file_util::ReadFileToString(log_file_name_,
                                                           &contents);
         if (!log_has_been_dumped)
-          PlatformThread::Sleep(100);
+          base::PlatformThread::Sleep(100);
       } while (!log_has_been_dumped && max_tries--);
       ASSERT_TRUE(log_has_been_dumped) << "Failed to read the log file";
 
       // Parse the contents to get average.
       int64 average = 0;
       const std::string average_str("average = ");
       std::string::size_type pos = contents.find(
           "Histogram: MPArch.RWH_TabSwitchPaintDuration", 0);
       std::string::size_type comma_pos;
       std::string::size_type number_length;
@@ skipping 60 matching lines @@
 TEST_F(TabSwitchingUITest, TabSwitch) {
   RunTabSwitchingUITest("t", true);
 }
 
 TEST_F(TabSwitchingUITest, TabSwitchRef) {
   UseReferenceBuild();
   RunTabSwitchingUITest("t_ref", true);
 }
 
 }  // namespace