Roll src/third_party/skia a31f4e51d559..20ee171b98bd (10 commits)

https://skia.googlesource.com/skia.git/+log/a31f4e51d559..20ee171b98bd


git log a31f4e51d559..20ee171b98bd --date=short --no-merges --format='%ad %ae %s'
2018-08-02 robertphillips@google.com Revert "Update GrTextureStripAtlas for DDLs"
2018-08-02 kjlubick@google.com Productionize PathKit
2018-08-02 fmalita@chromium.org [skottie/sksg] Move source files list to .gni
2018-08-02 robertphillips@google.com Update GrTextureStripAtlas for DDLs
2018-08-02 stani@google.com Prototype an Android lottie player
2018-08-02 halcanary@google.com tests: Move SkUTF tests to their own file.
2018-08-02 swiftshader-skia-autoroll@skia-buildbots.google.com.iam.gserviceaccount.com Roll third_party/externals/swiftshader 9e22c542d6be..dd4c8631343f (1 commits)
2018-08-02 jvanverth@google.com Fix minimization function for offset code
2018-08-02 benjaminwagner@google.com [infra] Ensure Mac xSAN backfill tasks can find Xcode.
2018-08-02 bsalomon@google.com Move mip map regen from GrGLProgram to GrGLGpu


Created with:
  gclient setdep -r src/third_party/skia@20ee171b98bd

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: Icecbe92f71210720d4f37bae7fe8352f71039fe0
Reviewed-on: https://chromium-review.googlesource.com/1160788Reviewed-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@{#580306}

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': 'a31f4e51d55989f0d580784ef15fc8c9f51202c5',
+  'skia_revision': '20ee171b98bd4faf1791d0052f140491f23b9555',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling V8
   # and whatever else without interference from each other.