Roll src/third_party/skia 77fdf66946d2..87e3bef6f82f (2 commits)

https://skia.googlesource.com/skia.git/+log/77fdf66946d2..87e3bef6f82f

git log 77fdf66946d2..87e3bef6f82f --date=short --first-parent --format='%ad %ae %s'
2020-02-07 brianosman@google.com Reland "Switch runtime SkSL to always sample at explicit coords"
2020-02-07 brianosman@google.com Roll libgifcodec

Created with:
  gclient setdep -r src/third_party/skia@87e3bef6f82f

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 scroggo@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
Bug: None
Tbr: scroggo@google.com
Change-Id: I468b5ad1978ce480e633a704a743cba3476ee145
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2043927Reviewed-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@{#739403}

DEPS

@@ -171,7 +171,7 @@ 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': '77fdf66946d2a498945394fe0b7cb06e3895aa5f',
+  'skia_revision': '87e3bef6f82f14735ec34b3467986bdb5ec42634',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling V8
   # and whatever else without interference from each other.