Fix i18n-content HTML presubmit check

chrome/browser/web_dev_style/html_checker_test.py

 #!/usr/bin/env python
 # Copyright 2015 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 html_checker
 from os import path as os_path
 import re
 from sys import path as sys_path
 import test_util
@@ skipping 122 matching lines @@
       'i18n-content="foo-"',
       'i18n-content="Foo"',
     ]
     for line in lines:
       self.ShouldFailCheck(line, self.checker.I18nContentJavaScriptCaseCheck)
 
   def testI18nContentJavaScriptCaseCheckPasses(self):
     lines = [
       ' i18n-content="abc" ',
       'i18n-content="fooBar"',
+      'i18n-content="validName" attr="invalidName_"',
       '<div i18n-content="exampleTitle"',
     ]
     for line in lines:
       self.ShouldPassCheck(line, self.checker.I18nContentJavaScriptCaseCheck)
 
   def testLabelCheckFails(self):
     lines = [
       ' for="abc"',
       "for=    ",
       " \tfor=    ",
       "   for="
     ]
     for line in lines:
       self.ShouldFailCheck(line, self.checker.LabelCheck)
 
   def testLabelCheckPass(self):
     lines = [
       ' my-for="abc" ',
       ' myfor="abc" ',
       " <for",
     ]
     for line in lines:
       self.ShouldPassCheck(line, self.checker.LabelCheck)
 
 
 if __name__ == '__main__':
   unittest.main()