Roll src/third_party/skia 63b4d5880a5b..a268dfb74add (3 commits)

https://skia.googlesource.com/skia.git/+log/63b4d5880a5b..a268dfb74add

git log 63b4d5880a5b..a268dfb74add --date=short --no-merges --format='%ad %ae %s'
2019-08-28 recipe-mega-autoroller@chops-service-accounts.iam.gserviceaccount.com Roll recipe dependencies (trivial).
2019-08-28 bungeman@google.com Add test for baseline snapping.
2019-08-28 dragonbear@google.com Override operator delete for GrCpuBuffer

Created with:
  gclient setdep -r src/third_party/skia@a268dfb74add

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 stani@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=stani@google.com

Bug: None
Change-Id: I3a0b2a4837eeb732b990b5b5d7c25d3b32a708ce
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1772309Reviewed-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@{#691268}

DEPS

@@ -162,7 +162,7 @@ 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': '63b4d5880a5bb3553ce9283400152fa5ed9821f6',
+  'skia_revision': 'a268dfb74add0aeb299800b4b2d88ed9c8c1ca4c',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling V8
   # and whatever else without interference from each other.