Make the windows_version.h functions threadsafe by using a singleton.

base/file_version_info_win.cc

-// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
+// Copyright (c) 2011 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/file_version_info_win.h"
 
 #include <windows.h>
 
 #include "base/file_path.h"
 #include "base/file_version_info.h"
 #include "base/logging.h"
 #include "base/path_service.h"
 #include "base/threading/thread_restrictions.h"
 
-// This has to be last.
-#include <strsafe.h>
-
 FileVersionInfoWin::FileVersionInfoWin(void* data, int language, int code_page)
     : language_(language), code_page_(code_page) {
   base::ThreadRestrictions::AssertIOAllowed();
   data_.reset((char*) data);
   fixed_file_info_ = NULL;
   UINT size;
   ::VerQueryValue(data_.get(), L"\\", (LPVOID*)&fixed_file_info_, &size);
 }
 
 FileVersionInfoWin::~FileVersionInfoWin() {
@@ skipping 148 matching lines @@
   return false;
 }
 
 std::wstring FileVersionInfoWin::GetStringValue(const wchar_t* name) {
   std::wstring str;
   if (GetValue(name, &str))
     return str;
   else
     return L"";
 }