It should be possible to run with --enable-accelerated-2d-canvas but not --enable-accelerated-compositing. It doesn't have to be fast (will use readback and software compositing), but it should work.
Created attachment 65279 [details] Patch
Attachment 65279 [details] did not build on gtk: Build output: http://queues.webkit.org/results/3776570
Created attachment 65293 [details] Patch
Looks good to me!
Comment on attachment 65293 [details] Patch Looks good to me.
Committed r65921: <http://trac.webkit.org/changeset/65921>