Removing webkit-prefixed image data HD APIs from 2D canvas

BUG=277205
R=senorblanco@chromium.org

Review URL: https://codereview.chromium.org/215193002

git-svn-id: svn://svn.chromium.org/blink/trunk@170324 bbb929c8-8fbe-4397-9dbb-9b2b20218538