The shader translator (which is part of ANGLE) is needed for the ACCELERATED_COMPOSITING path.
Created attachment 58270 [details] Proposed patch
Comment on attachment 58270 [details] Proposed patch ok.
Comment on attachment 58270 [details] Proposed patch Clearing flags on attachment: 58270 Committed r60954: <http://trac.webkit.org/changeset/60954>
All reviewed patches have been landed. Closing bug.