Roll src/third_party/angle 50919254cbc7..c2f1f6188127 (2 commits)

https://chromium.googlesource.com/angle/angle.git/+log/50919254cbc7..c2f1f6188127

git log 50919254cbc7..c2f1f6188127 --date=short --no-merges --format='%ad %ae %s'
2019-11-08 lehoangq@gmail.com Always use MTLPixelFormatBGRA8Unorm for SurfaceMtl.
2019-11-08 jonahr@google.com Reset texture swizzle state to default after LUMA workaround

Created with:
  gclient setdep -r src/third_party/angle@c2f1f6188127

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 jonahr@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_optional_gpu_tests_rel
TBR=jonahr@google.com

Bug: chromium:1022080
Change-Id: I8e90d828cd012b89d9946f042bf4d838952c7f0e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1907276Reviewed-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@{#714002}

DEPS

@@ -184,7 +184,7 @@ 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': '50919254cbc716d09703f93c2d38a0368809dbda',
+  'angle_revision': 'c2f1f618812724db5632820dc25480057fcea640',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling SwiftShader
   # and whatever else without interference from each other.