Histograms.xml python script housekeeping

tools/metrics/histograms/update_policies.py

 # Copyright 2013 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.
 
 """Updates EnterprisePolicies enum in histograms.xml file with policy
 definitions read from policy_templates.json.
 
 If the file was pretty-printed, the updated version is pretty-printed too.
 """
 
 import os
 import re
 import sys
 
 from ast import literal_eval
 from optparse import OptionParser
 from xml.dom import minidom
 
+sys.path.append(os.path.join(os.path.dirname(__file__), '..', 'common'))
+from diff_util import PromptUserToAcceptDiff
+import path_util
+
 import print_style
 
-# Import the metrics/common module.
-sys.path.append(os.path.join(os.path.dirname(__file__), '..', 'common'))
-from diff_util import PromptUserToAcceptDiff
-
-HISTOGRAMS_PATH = 'histograms.xml'
-POLICY_TEMPLATES_PATH = (
-    '../../../components/policy/resources/policy_templates.json')
+HISTOGRAMS_PATH = path_util.GetHistogramsFile()
+POLICY_TEMPLATES_PATH = 'components/policy/resources/policy_templates.json'
 ENUM_NAME = 'EnterprisePolicies'
 
 class UserError(Exception):
   def __init__(self, message):
     Exception.__init__(self, message)
 
   @property
   def message(self):
     return self.args[0]
 
@@ skipping 69 matching lines @@
     node.attributes['label'] = ParsePlaceholders(policy['caption'])
     policy_enum_node.appendChild(node)
 
 
 def main():
   if len(sys.argv) > 1:
     print >>sys.stderr, 'No arguments expected!'
     sys.stderr.write(__doc__)
     sys.exit(1)
 
-  with open(POLICY_TEMPLATES_PATH, 'rb') as f:
+  with open(path_util.GetInputFile(POLICY_TEMPLATES_PATH), 'rb') as f:
     policy_templates = literal_eval(f.read())
   with open(HISTOGRAMS_PATH, 'rb') as f:
     histograms_doc = minidom.parse(f)
     f.seek(0)
     xml = f.read()
 
   UpdateHistogramDefinitions(policy_templates, histograms_doc)
   new_xml = print_style.GetPrintStyle().PrettyPrintNode(histograms_doc)
   if PromptUserToAcceptDiff(xml, new_xml, 'Is the updated version acceptable?'):
     with open(HISTOGRAMS_PATH, 'wb') as f:
       f.write(new_xml)
 
 
 if __name__ == '__main__':
   try:
     main()
   except UserError as e:
     print >>sys.stderr, e.message
     sys.exit(1)