Add use counter for insertAdjacentText and insertAdjacentElement

These two are non standard IE extensions.

BUG=286321

Review URL: https://chromiumcodereview.appspot.com/23638009

git-svn-id: svn://svn.chromium.org/blink/trunk@157455 bbb929c8-8fbe-4397-9dbb-9b2b20218538