web_dev_style: tweak varNamesLikeThis check to detect endsWithUnder_

chrome/browser/web_dev_style/js_checker.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.
 
 """Presubmit script for Chromium JS resources.
 
 See chrome/browser/PRESUBMIT.py
 """
 
 import regex_check
@@ skipping 58 matching lines @@
         "Please only use this.$.localId, not element.$.localId")
 
   def WrapperTypeCheck(self, i, line):
     """Check for wrappers (new String()) instead of builtins (string)."""
     return self.RegexCheck(i, line,
         r"(?:/\*)?\*.*?@(?:param|return|type) ?"     # /** @param/@return/@type
         r"{[^}]*\b(String|Boolean|Number)\b[^}]*}",  # {(Boolean|Number|String)}
         "Don't use wrapper types (i.e. new String() or @type {String})")
 
   def VarNameCheck(self, i, line):
-    """See the style guide. http://goo.gl/uKir6"""
+    """See the style guide. http://goo.gl/eQiXVW"""
     return self.RegexCheck(i, line,
-        r"var (?!g_\w+)([a-z]*[_$][\w_$]*)(?<! \$)",
-        "Please use var namesLikeThis <http://goo.gl/uKir6>")
+        r"var (?!g_\w+)(_?[a-z][a-zA-Z]*[_$][\w_$]*)(?<! \$)",
+        "Please use var namesLikeThis <https://goo.gl/eQiXVW>")
 
   def _GetErrorHighlight(self, start, length):
     """Takes a start position and a length, and produces a row of '^'s to
        highlight the corresponding part of a string.
     """
     return start * ' ' + length * '^'
 
   def RunChecks(self):
     """Check for violations of the Chromium JavaScript style guide. See
        http://chromium.org/developers/web-development-style-guide#TOC-JavaScript
@@ skipping 28 matching lines @@
             f.LocalPath()] + error_lines
         results.append(self.output_api.PresubmitError('\n'.join(error_lines)))
 
     if results:
       results.append(self.output_api.PresubmitNotifyResult(
           'See the JavaScript style guide at '
           'http://www.chromium.org/developers/web-development-style-guide'
           '#TOC-JavaScript'))
 
     return results