Roll ANGLE from 5ac807b26749 to b4efc051da9d (7 revisions)

https://chromium.googlesource.com/angle/angle.git/+log/5ac807b26749..b4efc051da9d

2020-08-29 jmadill@chromium.org Enable -Wdeprecated-copy.
2020-08-29 jmadill@chromium.org Force impicit fallthrough off in xxhash.
2020-08-29 syoussefi@chromium.org Make copy*Texture parameters consistent for level indices
2020-08-28 cclao@google.com Vulkan: Use context staging buffer for CopyTexSubImage
2020-08-28 timvp@google.com Convert unordered_map to absl::flat_hash_map for select files
2020-08-28 jmadill@chromium.org Enable MSVC warning 4312.
2020-08-28 lehoangq@gmail.com Metal: autogen for EXT_occlusion_query_boolean.

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 courtneygo@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: courtneygo@google.com
Change-Id: Ibf2fdad9a7df77fe7d955cb8dbe9b1e1e634addc
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2383038Reviewed-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@{#802887}

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': '5ac807b267493118d5184fbe4ef9cabcbbb77944',
+  'angle_revision': 'b4efc051da9dc884087f1ace8185d410d4349d02',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling SwiftShader
   # and whatever else without interference from each other.