Roll src/third_party/angle 34e5a96edc3e..8dfc2b05d987 (2 commits)

https://chromium.googlesource.com/angle/angle.git/+log/34e5a96edc3e..8dfc2b05d987

git log 34e5a96edc3e..8dfc2b05d987 --date=short --first-parent --format='%ad %ae %s'
2019-11-25 jmadill@chromium.org Update codegen presubmit error.
2019-11-25 lehoangq@gmail.com Metal: support ANGLE_instance_arrays/EXT_instance_arrays

Created with:
  gclient setdep -r src/third_party/angle@8dfc2b05d987

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/angle-chromium-autoroll
Please CC cwallez@google.com on the revert to ensure that a human
is aware of the problem.

To report a problem with the AutoRoller itself, please file a bug:
https://bugs.chromium.org/p/skia/issues/entry?template=Autoroller+Bug

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+/master/autoroll/README.md

Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel;luci.chromium.try:linux_optional_gpu_tests_rel;luci.chromium.try:mac_optional_gpu_tests_rel;luci.chromium.try:win_optional_gpu_tests_rel
Bug: None
Tbr: cwallez@google.com
Change-Id: I505408e60bb467eb193324bd7314f5ca76dc8e48
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1934688Reviewed-by: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>
Commit-Queue: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#718872}

DEPS

@@ -184,7 +184,7 @@ vars = {
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling ANGLE
   # and whatever else without interference from each other.
-  'angle_revision': '34e5a96edc3ee51a607870d31fbfb9d10459df6f',
+  'angle_revision': '8dfc2b05d9871274779c56d8c5dec3399f97ee55',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling SwiftShader
   # and whatever else without interference from each other.