In discussions on the public WebGL mailing list, it was resolved to remove the automatic resizing of the viewport that is currently a result of changing the canvas's size. The backing store will still be allocated to the new size, but the automatic call to glViewport() needs to be removed.
Created attachment 48452 [details]
Comment on attachment 48452 [details]
Clearing flags on attachment: 48452
Committed r54625: <http://trac.webkit.org/changeset/54625>
All reviewed patches have been landed. Closing bug.