Roll src/third_party/skia 20ee171b98bd..578ef2847b72 (8 commits)

https://skia.googlesource.com/skia.git/+log/20ee171b98bd..578ef2847b72


git log 20ee171b98bd..578ef2847b72 --date=short --no-merges --format='%ad %ae %s'
2018-08-02 angle-skia-autoroll@skia-buildbots.google.com.iam.gserviceaccount.com Roll third_party/externals/angle2 cc73f241145d..cb4ae446080b (1 commits)
2018-08-02 herb@google.com Hoist path check
2018-08-02 brianosman@google.com For filled arcs, merge coverage by simply adding
2018-08-02 timliang@google.com implemented GrMtlBuffer for Metal gpu backend
2018-08-02 ethannicholas@google.com switched SkSL from std::map to std::unordered_map
2018-08-02 egdaniel@google.com Support using vulkan 1.1.
2018-08-02 kjlubick@google.com Make flutter roll happy
2018-08-02 egdaniel@google.com Have GrVkBackendContext take a VkPhysicalDeviceFeatures struct.


Created with:
  gclient setdep -r src/third_party/skia@578ef2847b72

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=scroggo@chromium.org

Change-Id: Ie082dacd968d0033e1399fedf6531a3674fa33a9
Reviewed-on: https://chromium-review.googlesource.com/1160945Reviewed-by: skia-chromium-autoroll <skia-chromium-autoroll@skia-buildbots.google.com.iam.gserviceaccount.com>
Commit-Queue: skia-chromium-autoroll <skia-chromium-autoroll@skia-buildbots.google.com.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#580375}

DEPS

@@ -105,7 +105,7 @@ 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': '20ee171b98bd4faf1791d0052f140491f23b9555',
+  'skia_revision': '578ef2847b72ca1d0e27e42f5a22d4c468a2caa3',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling V8
   # and whatever else without interference from each other.