Re-enable accelerated 2D Canvas on NVidia High Sierra

Re-enabling accelerated 2D Canvas, as without acceleration performance
was bad enough that Canvas2D became unusable in common cases. If
deciding between occasional visual corruption and unusable performance,
visual corruption seems to be the lesser issue.

Note that this keeps GPU Raster blacklisted. This is unfortunate, but
was only enabled 1yr ago, so should have less sites with a hard
dependency.

Bug: 773705
Cq-Include-Trybots: master.tryserver.chromium.android:android_optional_gpu_tests_rel;master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel
Change-Id: I1f33a6769fb6691b839f768326c153dfdedf13ff
Reviewed-on: https://chromium-review.googlesource.com/759236
Reviewed-by: Kenneth Russell <kbr@chromium.org>
Commit-Queue: Eric Karl <ericrk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#515315}
1 file changed