Update from https://crrev.com/312398

tools/clang/translation_unit/test_translation_unit.py

 #!/usr/bin/env python
 # Copyright (c) 2014 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.
 
 """Test for TranslationUnitGenerator tool."""
 
 import difflib
 import glob
 import json
@@ skipping 50 matching lines @@
     actual += '.filepaths'
     expected = actual + '.expected'
     print '[ RUN      ] %s' % os.path.relpath(actual)
     expected_output = actual_output = None
     with open(expected, 'r') as f:
       expected_output = f.readlines()
     with open(actual, 'r') as f:
       actual_output = f.readlines()
     has_same_filepaths = True
     for expected_line, actual_line in zip(expected_output, actual_output):
+      if '//' in actual_output:
+        if actual_output.split('//')[1] != expected_output:
+          sys.stdout.write('expected: %s' % expected_output)
+          sys.stdout.write('actual: %s' % actual_output.split('//')[1])
+          break
+        else:
+          continue
       if ntpath.basename(expected_line) != ntpath.basename(actual_line):
-        sys.stdout.write(ntpath.basename(expected_line))
-        sys.stdout.write(ntpath.basename(actual_line))
+        sys.stdout.write('expected: %s' % ntpath.basename(expected_line))
+        sys.stdout.write('actual: %s' % ntpath.basename(actual_line))
         has_same_filepaths = False
         break
     if not has_same_filepaths:
       failed += 1
       for line in difflib.unified_diff(expected_output, actual_output,
                                        fromfile=os.path.relpath(expected),
                                        tofile=os.path.relpath(actual)):
         sys.stdout.write(line)
       print '[  FAILED  ] %s' % os.path.relpath(actual)
       # Don't clean up the file on failure, so the results can be referenced
       # more easily.
       continue
     print '[       OK ] %s' % os.path.relpath(actual)
     passed += 1
     os.remove(actual)
 
   if failed == 0:
     os.remove(compile_database)
 
   print '[==========] %s ran.' % _NumberOfTestsToString(len(source_files))
   if passed > 0:
     print '[  PASSED  ] %s.' % _NumberOfTestsToString(passed)
   if failed > 0:
     print '[  FAILED  ] %s.' % _NumberOfTestsToString(failed)
 
 
 if __name__ == '__main__':
   sys.exit(main())