Switch to using setFilterLevel api instead of deprecated bit-flags for bitmap filtering

BUG=
R=jamesr@chromium.org

Review URL: https://codereview.chromium.org/19834003

git-svn-id: svn://svn.chromium.org/blink/trunk@154651 bbb929c8-8fbe-4397-9dbb-9b2b20218538