Make pretty_print.py look for a histograms.xml in the current working directory first.

tools/metrics/histograms/pretty_print.py

 #!/usr/bin/env python
 # 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.
 
 """Pretty-prints the histograms.xml file, alphabetizing tags, wrapping text
 at 80 chars, enforcing standard attribute ordering, and standardizing
 indentation.
 
 This is quite a bit more complicated than just calling tree.toprettyxml();
@@ skipping 304 matching lines @@
 
 
 def main():
   logging.basicConfig(level=logging.INFO)
 
   presubmit = ('--presubmit' in sys.argv)
 
   histograms_filename = 'histograms.xml'
   histograms_backup_filename = 'histograms.before.pretty-print.xml'
 
-  script_dir = path_utils.ScriptDir()
+  # If there is a histograms.xml in the current working directory, use that.
+  # Otherwise, use the one residing in the same directory as this script.
+  histograms_dir = os.getcwd()
+  if not os.path.isfile(os.path.join(histograms_dir, histograms_filename)):
+    histograms_dir = path_utils.ScriptDir()
 
-  histograms_pathname = os.path.join(script_dir, histograms_filename)
-  histograms_backup_pathname = os.path.join(script_dir,
+  histograms_pathname = os.path.join(histograms_dir, histograms_filename)
+  histograms_backup_pathname = os.path.join(histograms_dir,
                                             histograms_backup_filename)
 
-  logging.info('Loading %s...' % histograms_filename)
+  logging.info('Loading %s...' % os.path.relpath(histograms_pathname))
   with open(histograms_pathname, 'rb') as f:
     xml = f.read()
 
   # Check there are no CR ('\r') characters in the file.
   if '\r' in xml:
     logging.info('DOS-style line endings (CR characters) detected - these are '
                  'not allowed. Please run dos2unix %s' % histograms_filename)
     sys.exit(1)
 
   logging.info('Pretty-printing...')
@@ skipping 19 matching lines @@
   logging.info('Creating backup file %s' % histograms_backup_filename)
   shutil.move(histograms_pathname, histograms_backup_pathname)
 
   logging.info('Writing new %s file' % histograms_filename)
   with open(histograms_pathname, 'wb') as f:
     f.write(pretty)
 
 
 if __name__ == '__main__':
   main()