In order to pick up the upstream fixes for several linked bugs and more, it's necessary to roll ANGLE forward. Attempting that today.
Created attachment 399987 [details]
Note that there are important steps to take when updating ANGLE. See http://trac.webkit.org/wiki/UpdatingANGLE
Created attachment 399990 [details]
BTW, built and tested minimally locally with:
the test cases from Bug 210994:
and a couple of other pages.
Committed r262036: <https://trac.webkit.org/changeset/262036>
All reviewed patches have been landed. Closing bug and clearing flags on attachment 399990 [details].