Removes pinning code from TopSites as we no longer need it.

BUG=121584,122981
TEST=none
R=brettw@chromium.org,nirnimesh@chromium.org,estade@chromium.org

Review URL: https://chromiumcodereview.appspot.com/10050016

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@131857 0039d316-1c4b-4281-b951-d872f2087c98
11 files changed