Add a presubmit warning for not using UNIT_TEST in source 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 203 matching lines @@
 
   if len(files):
     return [ output_api.PresubmitError(
         'Do not #include <iostream> in header files, since it inserts static ' +
         'initialization into every file including the header. Instead, ' +
         '#include <ostream>. See http://crbug.com/94794',
         files) ]
   return []
 
 
+def _CheckNoUNIT_TESTInSourceFiles(input_api, output_api):
+  """Checks to make sure no source files use UNIT_TEST"""
+  problems = []
+  for f in input_api.AffectedFiles():
+    if (not f.LocalPath().endswith(('.cc', '.mm'))):
+      continue
+
+    for line_num, line in f.ChangedContents():
+      if 'UNIT_TEST' in line:
+        problems.append('    %s:%d' % (f.LocalPath(), line_num))
+
+  if not problems:
+    return []
+  return [output_api.PresubmitPromptWarning('UNIT_TEST is only for headers.\n' +
+      '\n'.join(problems))]
+
+
 def _CheckNoNewWStrings(input_api, output_api):
   """Checks to make sure we don't introduce use of wstrings."""
   problems = []
   for f in input_api.AffectedFiles():
     if (not f.LocalPath().endswith(('.cc', '.h')) or
         f.LocalPath().endswith('test.cc')):
       continue
 
     for line_num, line in f.ChangedContents():
       if 'wstring' in line:
@@ skipping 61 matching lines @@
 
 def _CommonChecks(input_api, output_api):
   """Checks common to both upload and commit."""
   results = []
   results.extend(input_api.canned_checks.PanProjectChecks(
       input_api, output_api, excluded_paths=_EXCLUDED_PATHS))
   results.extend(_CheckAuthorizedAuthor(input_api, output_api))
   results.extend(
     _CheckNoProductionCodeUsingTestOnlyFunctions(input_api, output_api))
   results.extend(_CheckNoIOStreamInHeaders(input_api, output_api))
+  results.extend(_CheckNoUNIT_TESTInSourceFiles(input_api, output_api))
   results.extend(_CheckNoNewWStrings(input_api, output_api))
   results.extend(_CheckNoDEPSGIT(input_api, output_api))
   results.extend(_CheckNoBannedFunctions(input_api, output_api))
   return results
 
 
 def _CheckSubversionConfig(input_api, output_api):
   """Verifies the subversion config file is correctly setup.
 
   Checks that autoprops are enabled, returns an error otherwise.
@@ skipping 123 matching lines @@
   for non_android_re in (aura_re, win_re):
     if all(re.search(non_android_re, f) for f in affected_files):
       possibly_android = False
       break
   if possibly_android:
     for f in change.AffectedFiles():
       if any(re.search(r, f.LocalPath()) for r in android_re_list):
         preferred.append('android')
         break
   return preferred