Make JSON validity presubmit test less stringent.

PRESUBMIT_test.py

 #!/usr/bin/env python
 # 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.
 
 import glob
 import json
 import os
 import re
 import subprocess
@@ skipping 452 matching lines @@
                 ]
     input_api.files = [MockFile(filename, contents)]
     self.assertEqual(None,
                      PRESUBMIT._GetJSONParseError(input_api, filename))
 
   def testFailure(self):
     input_api = MockInputApi()
     test_data = [
       ('invalid_json_1.json',
        ['{ x }'],
-       'Expecting property name: line 1 column 2 (char 2)'),
+       'Expecting property name:'),
       ('invalid_json_2.json',
        ['// Hello world!',
         '{ "hello": "world }'],
-       'Unterminated string starting at: line 2 column 12 (char 12)'),
+       'Unterminated string starting at:'),
       ('invalid_json_3.json',
        ['{ "a": "b", "c": "d", }'],
-       'Expecting property name: line 1 column 22 (char 22)'),
+       'Expecting property name:'),
       ('invalid_json_4.json',
        ['{ "a": "b" "c": "d" }'],
-       'Expecting , delimiter: line 1 column 11 (char 11)'),
+       'Expecting , delimiter:'),
       ]
 
     input_api.files = [MockFile(filename, contents)
                        for (filename, contents, _) in test_data]
 
     for (filename, _, expected_error) in test_data:
       actual_error = PRESUBMIT._GetJSONParseError(input_api, filename)
-      self.assertEqual(expected_error, str(actual_error))
+      self.assertTrue(expected_error in str(actual_error),
+                      "'%s' not found in '%s'" % (expected_error, actual_error))
 
   def testNoEatComments(self):
     input_api = MockInputApi()
     file_with_comments = 'file_with_comments.json'
     contents_with_comments = ['// This is a comment.',
                               '{',
                               '  "key1": ["value1", "value2"],',
                               '  "key2": 3  // This is an inline comment.',
                               '}'
                               ]
@@ skipping 140 matching lines @@
                        for (filename, contents, _) in test_data]
 
     for (filename, _, expected_error) in test_data:
       actual_error = PRESUBMIT._GetIDLParseError(input_api, filename)
       self.assertTrue(expected_error in str(actual_error),
                       "'%s' not found in '%s'" % (expected_error, actual_error))
 
 
 if __name__ == '__main__':
   unittest.main()