Tolerate the form 20xx-20xx for copyrights since it's used in a few headers.

TEST=none
BUG=28291

Review URL: http://codereview.chromium.org/556059

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@37415 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/PRESUBMIT.py b/PRESUBMIT.py
index 7339de1..d0b0a41 100644
--- a/PRESUBMIT.py
+++ b/PRESUBMIT.py
@@ -20,8 +20,8 @@
 )
 
 _LICENSE_HEADER = (
-     r".*? Copyright \(c\) 20\d\d The Chromium Authors\. All rights reserved\."
-       "\n"
+     r".*? Copyright \(c\) 20[0-9\-]{2,7} The Chromium Authors\. All rights "
+       r"reserved\." "\n"
      r".*? Use of this source code is governed by a BSD-style license that can "
        "be\n"
      r".*? found in the LICENSE file\."