Roll src/third_party/skia/ 27f5a0df4..8517631bf (2 commits; 1 trivial rolls)

https://skia.googlesource.com/skia.git/+log/27f5a0df4a28..8517631bf410

$ git log 27f5a0df4..8517631bf --date=short --no-merges --format='%ad %ae %s'
2018-05-24 angle-skia-autoroll Roll third_party/externals/angle2/ 586750168..b001528ff (4 commits)

Created with:
  roll-dep src/third_party/skia


The AutoRoll server is located here: https://autoroll.skia.org

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+/master/autoroll/README.md

If the roll is causing failures, please contact the current sheriff, who should
be CC'd on the roll, and stop the roller if necessary.


CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel;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=allanmac@chromium.org

Change-Id: Ic59d9bc073c68ce102eeb6f51d74731be60cadc4
Reviewed-on: https://chromium-review.googlesource.com/1071235
Commit-Queue: skia-chromium-autoroll <skia-chromium-autoroll@skia-buildbots.google.com.iam.gserviceaccount.com>
Reviewed-by: skia-chromium-autoroll <skia-chromium-autoroll@skia-buildbots.google.com.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#561426}

DEPS

@@ -96,7 +96,7 @@ 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': '27f5a0df4a280934d662e5a976b9927018be628e',
+  'skia_revision': '8517631bf41089f0d5805741c98f4d0d5f1a7beb',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling V8
   # and whatever else without interference from each other.