Roll src/third_party/skia df18296f9844..fb6a1abe4567 (1 commits)

https://skia.googlesource.com/skia.git/+log/df18296f9844..fb6a1abe4567

git log df18296f9844..fb6a1abe4567 --date=short --no-merges --format='%ad %ae %s'
2019-10-15 mtklein@google.com try un-teaching TSAN about Mac semaphores

Created with:
  gclient setdep -r src/third_party/skia@fb6a1abe4567

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/skia-autoroll
Please CC csmartdalton@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-blink-rel;luci.chromium.try:linux-chromeos-compile-dbg;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=csmartdalton@google.com

Bug: None
Change-Id: I5b8244727d408b0cb1c5466fa74d8ee6bc8a41c0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1862242Reviewed-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@{#706029}

DEPS

@@ -167,7 +167,7 @@ vars = {
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling Skia
   # and whatever else without interference from each other.
-  'skia_revision': 'df18296f9844e0668eae13af5819166e8f18061e',
+  'skia_revision': 'fb6a1abe45673659c603241569db9128fe5691d7',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling V8
   # and whatever else without interference from each other.