Roll src/third_party/angle 8e7d9d6c2326..ef4c25e71c32 (1 commits)

https://chromium.googlesource.com/angle/angle.git/+log/8e7d9d6c2326..ef4c25e71c32

git log 8e7d9d6c2326..ef4c25e71c32 --date=short --no-merges --format='%ad %ae %s'
2019-10-09 geofflang@chromium.org GL: Skip buffer validation for transform feedback buffers.

Created with:
  gclient setdep -r src/third_party/angle@ef4c25e71c32

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/+/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=geofflang@google.com

Bug: None
Change-Id: Ia4d7515f2a0d21d53007a83f76c7585588f0ab72
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1849262Reviewed-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@{#704231}

DEPS

@@ -179,7 +179,7 @@ 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': '8e7d9d6c2326a36ff57335ceeb41eb86cb639a7f',
+  'angle_revision': 'ef4c25e71c32487feade5e9f8e79cb569545b846',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling SwiftShader
   # and whatever else without interference from each other.