Make CreateDirectory consistent on Win and Posix when directory exists.

base/file_util_win.cc

 // Copyright (c) 2006-2008 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_util.h"
 
 #include <windows.h>
 #include <shellapi.h>
 #include <shlobj.h>
 #include <time.h>
@@ skipping 401 matching lines @@
 
   if (count == 50) {
     return false;
   }
 
   new_temp_path->assign(path_to_create);
   return true;
 }
 
 bool CreateDirectory(const std::wstring& full_path) {
+  if (PathExists(full_path))
+    return true;
   int err = SHCreateDirectoryEx(NULL, full_path.c_str(), NULL);
   return err == ERROR_SUCCESS;
 }
 
 bool GetFileSize(const std::wstring& file_path, int64* file_size) {
   ScopedHandle file_handle(
       CreateFile(file_path.c_str(), GENERIC_READ,
                  FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, NULL,
                  OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL));
 
@@ skipping 204 matching lines @@
       return (file_type_ & FileEnumerator::DIRECTORIES) ? cur_file : Next();
     }
 
     if ((file_type_ & FileEnumerator::DIRECTORIES) == 0)
       return Next();
   }
   return (file_type_ & FileEnumerator::FILES) ? cur_file : Next();
 }
 
 }  // namespace file_util
-