Disable MSAA for slow paths if avoid_stencil_buffers workaround is set.

avoid_stencil_buffers blocks MSAA support in Skia.  If the compositor requests
MSAA surfaces, rendering will fail.

R=ericrk@chromium.org
TBR=vmiura@chromium.org
BUG=749438,713854

(cherry picked from commit d676a966d41ac183b4b87ae494c36f1744b048f2)

Cq-Include-Trybots: master.tryserver.blink:linux_trusty_blink_rel
Change-Id: I887888845a2c1ee18dbccff6e96aa6cd1eac3df2
Reviewed-on: https://chromium-review.googlesource.com/597321
Reviewed-by: Eric Karl <ericrk@chromium.org>
Commit-Queue: Victor Miura <vmiura@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#491446}
Reviewed-on: https://chromium-review.googlesource.com/598630
Reviewed-by: Victor Miura <vmiura@chromium.org>
Cr-Commit-Position: refs/branch-heads/3163@{#242}
Cr-Branched-From: ff259bab28b35d242e10186cd63af7ed404fae0d-refs/heads/master@{#488528}
3 files changed