Roll src/third_party/angle 4546c5cefa0e..d8c4b5fb80d4 (5 commits)

https://chromium.googlesource.com/angle/angle.git/+log/4546c5cefa0e..d8c4b5fb80d4

git log 4546c5cefa0e..d8c4b5fb80d4 --date=short --first-parent --format='%ad %ae %s'
2020-02-04 lexa.knyazev@gmail.com Expose ASTC 2D on OpenGL
2020-02-04 lexa.knyazev@gmail.com Update S3TC GL extension strings
2020-02-04 angle-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/vulkan-loader/src fb94ccddb725..807f14657a25 (2 commits)
2020-02-04 angle-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/glslang/src 5e86b28ffb81..540662253ea3 (1 commits)
2020-02-03 geofflang@chromium.org Share scratch buffers between contexts.

Created with:
  gclient setdep -r src/third_party/angle@d8c4b5fb80d4

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 cnorthrop@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-asan;luci.chromium.try:win_optional_gpu_tests_rel
Bug: chromium:1030835
Tbr: cnorthrop@google.com
Change-Id: I41a3fe1c35e23d5118cbbb6aa866ce519714a127
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2037426Reviewed-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@{#738291}

DEPS

@@ -188,7 +188,7 @@ 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': '4546c5cefa0eb11d423b60ac98802e671510a562',
+  'angle_revision': 'd8c4b5fb80d417343b52273515e046a37eda7138',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling SwiftShader
   # and whatever else without interference from each other.