Roll ANGLE from 9ff58ddd0adf to b44af6625286 (2 revisions)

https://chromium.googlesource.com/angle/angle.git/+log/9ff58ddd0adf..b44af6625286

2020-09-22 courtneygo@google.com Vulkan: Fix racy access to VkPipelineCache
2020-09-22 cclao@google.com Vulkan: Add a alpha to coverage test

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 syoussefi@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/+doc/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;luci.chromium.try:linux-swangle-try-x64;luci.chromium.try:win-swangle-try-x86
Bug: None
Tbr: syoussefi@google.com
Change-Id: I81513cb6f9443f73f870fc140f4990dec22f64a7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2424727Reviewed-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@{#809583}

DEPS

@@ -207,7 +207,7 @@ 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': '9ff58ddd0adf823ad753e36ea652b9b664c54c79',
+  'angle_revision': 'b44af6625286df933a688779d139ec33cd3e492a',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling SwiftShader
   # and whatever else without interference from each other.