Histograms.xml python script housekeeping

tools/metrics/histograms/update_use_counter_css.py

 #!/usr/bin/env python
 # Copyright 2014 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.
 
 """Scans the Chromium source of UseCounter, formats the Feature enum for
 histograms.xml and merges it. This script can also generate a python code
 snippet to put in uma.py of Chromium Dashboard. Make sure that you review the
 output for correctness.
 """
 
 import optparse
 import os
 import re
 import sys
 
-sys.path.append(os.path.join(os.path.dirname(__file__), '..', 'common'))
-from update_histogram_enum import ReadHistogramValues
-from update_histogram_enum import UpdateHistogramFromDict
-from update_use_counter_feature_enum import PrintEnumForDashboard
+import histograms_path
+import update_histogram_enum
+import update_use_counter_feature_enum
 
 
-USE_COUNTER_CPP_PATH = \
-    '../../../third_party/WebKit/Source/core/frame/UseCounter.cpp'
+USE_COUNTER_CPP_PATH = 'third_party/WebKit/Source/core/frame/UseCounter.cpp'
 
 
 def EnumToCssProperty(enum_name):
   """Converts a camel cased enum name to the lower case CSS property."""
   # The first group also searches for uppercase letters to account for single
   # uppercase letters, such as in "ZIndex" that need to convert to "z-index".
   return re.sub(r'([a-zA-Z])([A-Z])', r'\1-\2', enum_name).lower()
 
 
 def ReadCssProperties(filename):
   # Read the file as a list of lines
-  with open(filename) as f:
+  with open(histograms_path.GetInputFile(filename)) as f:
     content = f.readlines()
 
   # Looking for a line like "case CSSPropertyGrid: return 453;".
   ENUM_REGEX = re.compile(r"""CSSProperty(.*):  # capture the enum name
                               \s*return\s*
                               ([0-9]+)          # capture the id
                               """, re.VERBOSE)
 
   properties = {}
   for line in content:
@@ skipping 10 matching lines @@
   parser = optparse.OptionParser()
   parser.add_option('--for-dashboard', action='store_true', dest='dashboard',
                     default=False,
                     help='Print enum definition formatted for use in uma.py of '
                     'Chromium dashboard developed at '
                     'https://github.com/GoogleChrome/chromium-dashboard')
   options, args = parser.parse_args()
 
   if options.dashboard:
     enum_dict = ReadCssProperties(USE_COUNTER_CPP_PATH)
-    PrintEnumForDashboard(enum_dict)
+    update_use_counter_feature_enum.PrintEnumForDashboard(enum_dict)
   else:
-    UpdateHistogramFromDict(
+    update_histogram_enum.UpdateHistogramFromDict(
         'MappedCSSProperties', ReadCssProperties(USE_COUNTER_CPP_PATH),
         USE_COUNTER_CPP_PATH)