Roll src/third_party/angle 06f4f3e13c49..4b94d7bb4fbe (2 commits)

https://chromium.googlesource.com/angle/angle.git/+log/06f4f3e13c49..4b94d7bb4fbe

git log 06f4f3e13c49..4b94d7bb4fbe --date=short --first-parent --format='%ad %ae %s'
2020-03-31 jonahr@google.com Split EGL_CHROMIUM_sync_control into EGL_ANGLE_sync_control_rate
2020-03-31 kbr@chromium.org Apply limitMaxMSAASamplesTo4 workaround to macOS.

Created with:
  gclient setdep -r src/third_party/angle@4b94d7bb4fbe

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 cwallez@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:1064078
Tbr: cwallez@google.com
Change-Id: I7a8964875bea0a7976be111a203ea3718427b029
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2131147Reviewed-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@{#755203}

DEPS

@@ -187,7 +187,7 @@ 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': '06f4f3e13c49e0c879d6479f940d0f26b5faa190',
+  'angle_revision': '4b94d7bb4fbed9018d198dfdc50c3aa5f9be3ddf',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling SwiftShader
   # and whatever else without interference from each other.