Roll src/third_party/angle d4c75347e4d3..29f7916fd56e (3 commits)

https://chromium.googlesource.com/angle/angle.git/+log/d4c75347e4d3..29f7916fd56e

git log d4c75347e4d3..29f7916fd56e --date=short --no-merges --format='%ad %ae %s'
2019-09-25 jmadill@chromium.org Vulkan: Store current Serial in RendererVk.
2019-09-25 ynovikov@chromium.org Temporarily disable SwiftShader everywhere.
2019-09-25 jonahr@google.com GLX: Forward XExposeEvents to parent window

Created with:
  gclient setdep -r src/third_party/angle@29f7916fd56e

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 ynovikov@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=ynovikov@google.com

Bug: chromium:1008100,chromium:991577
Change-Id: Ib83f0b48defba45f982a0e9ab4e9af5a35c8b795
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1825627Reviewed-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@{#699988}

DEPS

@@ -174,7 +174,7 @@ 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': 'd4c75347e4d386a3eed50d73a473621155d5fe16',
+  'angle_revision': '29f7916fd56ef664fdf80ced890204569a3994c9',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling SwiftShader
   # and whatever else without interference from each other.