Fix dependencies for create and upload SDK.

dart/tools/utils.py

 # Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 # This file contains a set of utilities functions used by other Python-based
 # scripts.
 
 import commands
 import os
 import platform
@@ skipping 252 matching lines @@
   else:
     return exit_code < 0
 
 
 def DiagnoseExitCode(exit_code, command):
   if IsCrashExitCode(exit_code):
     sys.stderr.write('Command: %s\nCRASHED with exit code %d (0x%x)\n' % (
         ' '.join(command), exit_code, exit_code & 0xffffffff))
 
 
+def Touch(name):
+  with file(name, 'a'):
+    os.utime(name, None)
+
+
 if __name__ == "__main__":
   import sys
   Main(sys.argv)