Roll ANGLE from 1a4f6e1f3ce1 to 93fc7d718e4c (4 revisions)

https://chromium.googlesource.com/angle/angle.git/+log/1a4f6e1f3ce1..93fc7d718e4c

2020-05-21 jonahr@google.com Add error-handling when getting Xcb window size
2020-05-21 geofflang@google.com Don't write alpha when blitting to a framebuffer with emulated alpha.
2020-05-21 xinyi.he@arm.com Vulkan: Remove GL_BGRX8_ANGLEX from configurations
2020-05-21 cclao@google.com Vulkan: change preferAggregateBarrierCalls to accomodate ARM on linux

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@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: chromium:1080984
Tbr: geofflang@google.com
Change-Id: I3c2a37c3d72c178e41f08e505a7f0d08fe136a8a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2212589Reviewed-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@{#771199}

DEPS

@@ -190,7 +190,7 @@ 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': '1a4f6e1f3ce170471a583f746664b4e501378adc',
+  'angle_revision': '93fc7d718e4c26d81d832a20de5e64953def0179',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling SwiftShader
   # and whatever else without interference from each other.