Histograms.xml python script housekeeping

tools/metrics/rappor/pretty_print.py

 #!/usr/bin/env python
 # Copyright 2015 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.
 
 import logging
+import os
 import sys
-import os
 
-# Import the metrics/common module for pretty print xml.
 sys.path.append(os.path.join(os.path.dirname(__file__), '..', 'common'))
 import models
 import presubmit_util
 
 
 # Model definitions for rappor.xml content
 _SUMMARY_TYPE = models.TextNodeType('summary')
 
 _PARAMETERS_TYPE = models.ObjectNodeType('parameters',
     int_attributes=[
@@ skipping 155 matching lines @@
   return RAPPOR_XML_TYPE.PrettyPrint(comments, config)
 
 
 def main(argv):
   presubmit_util.DoPresubmitMain(argv, 'rappor.xml', 'rappor.old.xml',
                                  'pretty_print.py', UpdateXML)
 
 
 if '__main__' == __name__:
   sys.exit(main(sys.argv))