Roll src/third_party/angle 6c4ff5ddab07..8f2d41d1be9d (1 commits)

https://chromium.googlesource.com/angle/angle.git/+log/6c4ff5ddab07..8f2d41d1be9d

git log 6c4ff5ddab07..8f2d41d1be9d --date=short --no-merges --format='%ad %ae %s'
2019-09-20 angle-autoroll@skia-public.iam.gserviceaccount.com Roll ./third_party/glslang/src caca1d1cc46e..f7a48b153f2a (1 commits)

Created with:
  gclient setdep -r src/third_party/angle@8f2d41d1be9d

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 geofflang@chromium.org 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
TBR=geofflang@chromium.org

Bug: chromium:None
Change-Id: I024f35ec1dac5dc27f1e86f5a36ee4626bcd99fd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1815672Reviewed-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@{#698416}

DEPS

@@ -174,7 +174,7 @@ 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': '6c4ff5ddab07d5f8a96c72e705265e2e35fdaba8',
+  'angle_revision': '8f2d41d1be9ddf3c48e3de17b76d3d358b75f03e',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling SwiftShader
   # and whatever else without interference from each other.