Exclude emacs auto-save files like .#foo.rst .

BUG= none
NOTRY=true
  (documentation-only change)

Review URL: https://chromiumcodereview.appspot.com/23484066

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@225050 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 225050