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

chrome/test/automation/automation_proxy_uitest.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 <string>
 
 #include "app/app_switches.h"
 #include "app/message_box_flags.h"
 #include "base/command_line.h"
 #include "base/compiler_specific.h"
@@ skipping 1538 matching lines @@
   scoped_refptr<TabProxy> tab(window->GetTab(0));
   ASSERT_TRUE(tab.get());
 
   FilePath filename(test_data_directory_);
   filename = filename.AppendASCII("dom_automation_test_with_popup.html");
 
   ASSERT_EQ(AUTOMATION_MSG_NAVIGATION_SUCCESS,
             tab->NavigateToURL(net::FilePathToFileURL(filename)));
 
   // Allow some time for the popup to show up and close.
-  PlatformThread::Sleep(sleep_timeout_ms());
+  base::PlatformThread::Sleep(sleep_timeout_ms());
 
   std::wstring expected(L"string");
   std::wstring jscript = CreateJSString(L"\"" + expected + L"\"");
   std::wstring actual;
   ASSERT_TRUE(tab->ExecuteAndExtractString(L"", jscript, &actual));
   ASSERT_EQ(expected, actual);
 }
 
 class AutomationProxySnapshotTest : public UITest {
  protected:
@@ skipping 171 matching lines @@
   int diff_pixels_count = 0;
   for (int x = 0; x < img_size.width(); ++x) {
     for (int y = 0; y < img_size.height(); ++y) {
       if (*snapshot_bmp.getAddr32(x, y) != *reference_bmp.getAddr32(x, y)) {
         ++diff_pixels_count;
       }
     }
   }
   ASSERT_EQ(diff_pixels_count, 0);
 }