Remove unused ATL headers.

chrome/test/plugin/plugin_test.cpp

 // Copyright 2008-2009, Google Inc.
 // All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //    * Redistributions of source code must retain the above copyright
 // notice, this list of conditions and the following disclaimer.
 //    * Redistributions in binary form must reproduce the above
@@ skipping 22 matching lines @@
 //  Real
 //  QuickTime
 //  Windows Media Player
 //    -this includes both WMP plugins.  npdsplay.dll is the older one that
 //     comes with XP.  np-mswmp.dll can be downloaded from Microsoft and
 //     needs SP2 or Vista.
 
 #include <windows.h>
 #include <shellapi.h>
 #include <shlobj.h>
-#include <atlbase.h>
 #include <comutil.h>
 
 #include <stdlib.h>
 #include <string.h>
 #include <memory.h>
 
+#include <string>
+
 #include "base/file_path.h"
 #include "base/file_util.h"
 #include "base/registry.h"
 #include "chrome/browser/net/url_request_mock_http_job.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/chrome_paths.h"
 #include "chrome/test/automation/tab_proxy.h"
 #include "chrome/test/ui/ui_test.h"
 #include "net/base/net_util.h"
 #include "third_party/npapi/bindings/npapi.h"
@@ skipping 113 matching lines @@
 }
 
 // http://crbug.com/8690
 TEST_F(PluginTest, DISABLED_Java) {
   TestPlugin(L"Java.html", kShortWaitTimeout, false);
 }
 
 TEST_F(PluginTest, Silverlight) {
   TestPlugin(L"silverlight.html", kShortWaitTimeout, false);
 }