Add presubmit check for Google support URL format.

PRESUBMIT.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.
 
 """Top-level presubmit script for Chromium.
 
 See http://dev.chromium.org/developers/how-tos/depottools/presubmit-scripts
 for more details about the presubmit API built into depot_tools.
 """
 
@@ skipping 957 matching lines @@
   errors = []
   for f in input_api.AffectedFiles():
     errors.extend(_CheckForVersionControlConflictsInFile(input_api, f))
 
   results = []
   if errors:
     results.append(output_api.PresubmitError(
       'Version control conflict markers found, please resolve.', errors))
   return results
 
+def _CheckGoogleSupportAnswerUrl(input_api, output_api):
+  pattern = input_api.re.compile('support\.google\.com\/chrome.*/answer')
+  errors = []
+  for f in input_api.AffectedFiles():
+    for line_num, line in f.ChangedContents():
+      if pattern.search(line):
+        errors.append('    %s:%d %s' % (f.LocalPath(), line_num, line))
+
+  results = []
+  if errors:
+    results.append(output_api.PresubmitPromptWarning(
+      'Found Google support URL addressed by answer number. Please replace with '
+      'a p= identifier instead. See crbug.com/679462\n', errors))
+  return results
+
 
 def _CheckHardcodedGoogleHostsInLowerLayers(input_api, output_api):
   def FilterFile(affected_file):
     """Filter function for use with input_api.AffectedSourceFiles,
     below.  This filters out everything except non-test files from
     top-level directories that generally speaking should not hard-code
     service URLs (e.g. src/android_webview/, src/content/ and others).
     """
     return input_api.FilterSourceFile(
       affected_file,
@@ skipping 1301 matching lines @@
 
 def CheckChangeOnUpload(input_api, output_api):
   results = []
   results.extend(_CommonChecks(input_api, output_api))
   results.extend(_CheckValidHostsInDEPS(input_api, output_api))
   results.extend(
       input_api.canned_checks.CheckGNFormatted(input_api, output_api))
   results.extend(_CheckUmaHistogramChanges(input_api, output_api))
   results.extend(_AndroidSpecificOnUploadChecks(input_api, output_api))
   results.extend(_CheckSyslogUseWarning(input_api, output_api))
+  results.extend(_CheckGoogleSupportAnswerUrl(input_api, output_api))
   return results
 
 
 def GetTryServerMasterForBot(bot):
   """Returns the Try Server master for the given bot.
 
   It tries to guess the master from the bot name, but may still fail
   and return None.  There is no longer a default master.
   """
   # Potentially ambiguous bot names are listed explicitly.
@@ skipping 34 matching lines @@
   results.extend(input_api.canned_checks.CheckTreeIsOpen(
       input_api,
       output_api,
       json_url='http://chromium-status.appspot.com/current?format=json'))
 
   results.extend(input_api.canned_checks.CheckChangeHasBugField(
       input_api, output_api))
   results.extend(input_api.canned_checks.CheckChangeHasDescription(
       input_api, output_api))
   return results