Remove vestigal traces of side-pinning introduced in r101993 and removed in r134754

BUG=none
R=palmer@chromium.org
TBR=agl@chromium.org

Review URL: https://codereview.chromium.org/93713006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@242791 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 242791