Change default ReportErrorFileAndLine to use filename:lineno format.

presubmit_canned_checks.py

 # Copyright (c) 2012 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.
 
 """Generic presubmit checks that can be reused by other presubmit checks."""
 
 import os as _os
 _HERE = _os.path.dirname(_os.path.abspath(__file__))
 
 
@@ skipping 210 matching lines @@
         'Found a CR character in these files:', items=cr_files))
   if eof_files:
     outputs.append(output_api.PresubmitPromptWarning(
       'These files should end in one (and only one) newline character:',
       items=eof_files))
   return outputs
 
 
 def _ReportErrorFileAndLine(filename, line_num, dummy_line):
   """Default error formatter for _FindNewViolationsOfRule."""
-  return '%s, line %s' % (filename, line_num)
+  return '%s:%s' % (filename, line_num)
 
 
 def _FindNewViolationsOfRule(callable_rule, input_api, source_file_filter=None,
                              error_formatter=_ReportErrorFileAndLine):
   """Find all newly introduced violations of a per-line rule (a callable).
 
   Arguments:
     callable_rule: a callable taking a file extension and line of input and
       returning True if the rule is satisfied and False if there was a problem.
     input_api: object to enumerate the affected files.
@@ skipping 780 matching lines @@
     snapshot("checking description")
     results.extend(input_api.canned_checks.CheckChangeHasDescription(
         input_api, output_api))
     results.extend(input_api.canned_checks.CheckDoNotSubmitInDescription(
         input_api, output_api))
     snapshot("checking do not submit in files")
     results.extend(input_api.canned_checks.CheckDoNotSubmitInFiles(
         input_api, output_api))
   snapshot("done")
   return results