Add a presubmit check to prevent committing .rej/.orig patch files

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 gcl.
 """
 
@@ skipping 651 matching lines @@
   results.extend(_CheckNoNewWStrings(input_api, output_api))
   results.extend(_CheckNoDEPSGIT(input_api, output_api))
   results.extend(_CheckNoBannedFunctions(input_api, output_api))
   results.extend(_CheckNoPragmaOnce(input_api, output_api))
   results.extend(_CheckNoTrinaryTrueFalse(input_api, output_api))
   results.extend(_CheckUnwantedDependencies(input_api, output_api))
   results.extend(_CheckFilePermissions(input_api, output_api))
   results.extend(_CheckNoAuraWindowPropertyHInHeaders(input_api, output_api))
   results.extend(_CheckIncludeOrder(input_api, output_api))
   results.extend(_CheckForVersionControlConflicts(input_api, output_api))
+  results.extend(_CheckPatchFiles(input_api, output_api))
 
   if any('PRESUBMIT.py' == f.LocalPath() for f in input_api.AffectedFiles()):
     results.extend(input_api.canned_checks.RunUnitTestsInDirectory(
         input_api, output_api,
         input_api.PresubmitLocalPath(),
         whitelist=[r'.+_test\.py$']))
   return results
 
 
 def _CheckSubversionConfig(input_api, output_api):
@@ skipping 63 matching lines @@
     return [output_api.PresubmitPromptWarning(
         ('%s is not in AUTHORS file. If you are a new contributor, please visit'
         '\n'
         'http://www.chromium.org/developers/contributing-code and read the '
         '"Legal" section\n'
         'If you are a chromite, verify the contributor signed the CLA.') %
         author)]
   return []
 
 
+def _CheckPatchFiles(input_api, output_api):
+  problems = [f.LocalPath() for f in input_api.AffectedFiles()

[M-A Ruel, 2012/12/05 19:39:22]

In theory, you should put this one at +4 too on next line

[enne (OOO), 2012/12/05 19:46:44]

Oh? Are you suggesting to linebreak after the bracket? (Although in that case,
wouldn't it just be +2 indent?)

I'm happy to change it to whatever you want, I just don't quite follow. 
\noideadog{enne formatting Python code}

[M-A Ruel, 2012/12/05 19:51:08]

Actually, you are right it'd be +2, don't bother.

+      if f.LocalPath().endswith(('.orig', '.rej'))]
+  if problems:
+    return [output_api.PresubmitError(
+        "Don't commit .rej and .orig files.", problems)]
+  else:
+    return []
+
+
 def CheckChangeOnUpload(input_api, output_api):
   results = []
   results.extend(_CommonChecks(input_api, output_api))
   return results
 
 
 def CheckChangeOnCommit(input_api, output_api):
   results = []
   results.extend(_CommonChecks(input_api, output_api))
   # TODO(thestig) temporarily disabled, doesn't work in third_party/
@@ skipping 49 matching lines @@
       'win_aura',
       'win_rel',
   ]
 
   # Match things like path/aura/file.cc and path/file_aura.cc.
   # Same for chromeos.
   if any(re.search('[/_](aura|chromeos)', f) for f in files):
     trybots += ['linux_chromeos_clang:compile', 'linux_chromeos_asan']
 
   return trybots