Roll src/third_party/skia 7823aeb8d6da..5b6ccbb6b599 (4 commits)

https://skia.googlesource.com/skia.git/+log/7823aeb8d6da..5b6ccbb6b599

git log 7823aeb8d6da..5b6ccbb6b599 --date=short --no-merges --format='%ad %ae %s'
2019-10-31 benjaminwagner@google.com [infra] Upgrade MacBookAir to 10.15.
2019-10-31 herb@google.com ...finally!
2019-10-31 michaelludwig@google.com Move tessellation math into GrQuadUtils
2019-10-31 benjaminwagner@google.com Add Pixel4 jobs

Created with:
  gclient setdep -r src/third_party/skia@5b6ccbb6b599

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 jcgregorio@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=jcgregorio@google.com

Bug: None
Change-Id: Ib64a85da78e47841407032d75eb6d9066a2bd39f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1894255Reviewed-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@{#711477}

DEPS

@@ -172,7 +172,7 @@ 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': '7823aeb8d6da204568fe3c54683da5f3fc4f0d16',
+  'skia_revision': '5b6ccbb6b59974d80c095958cf3fd77fac194caa',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling V8
   # and whatever else without interference from each other.