Roll src/third_party/skia 6d1c0d4196f1..172bb44f2d66 (22 commits)

https://skia.googlesource.com/skia.git/+log/6d1c0d4196f1..172bb44f2d66

git log 6d1c0d4196f1..172bb44f2d66 --date=short --no-merges --format='%ad %ae %s'
2019-09-06 brianosman@google.com Make the size of program/pipeline caches configurable in GrContextOptions
2019-09-06 reed@google.com use scratch path to save on mallocs in drawAtlas
2019-09-06 robertphillips@google.com Remove IORefs from GrSurface
2019-09-06 skia-recreate-skps@skia-swarming-bots.iam.gserviceaccount.com Update Go deps
2019-09-06 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/angle2 0c35e0f44dbd..df0ce01870fa (5 commits)
2019-09-06 skia-autoroll@skia-public.iam.gserviceaccount.com Roll ../src e96090c3..64926377 (605 commits)
2019-09-06 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/swiftshader cf0e2fe12289..5d0faf9be9d7 (4 commits)
2019-09-06 recipe-mega-autoroller@chops-service-accounts.iam.gserviceaccount.com Roll recipe dependencies (trivial).
2019-09-05 recipe-mega-autoroller@chops-service-accounts.iam.gserviceaccount.com Roll recipe dependencies (trivial).
2019-09-05 recipe-mega-autoroller@chops-service-accounts.iam.gserviceaccount.com Roll recipe dependencies (trivial).
2019-09-05 herb@google.com Remove bool for RemoteStrike send
2019-09-05 recipe-mega-autoroller@chops-service-accounts.iam.gserviceaccount.com Roll recipe dependencies (trivial).
2019-09-05 reed@google.com reverse/restore order of verbs in path to be forward (normal)
2019-09-05 skia-recreate-skps@skia-swarming-bots.iam.gserviceaccount.com Update SKP version
2019-09-05 khushalsagar@chromium.org Reland: Only send the RemoteStrikes that have pending glyphs.
2019-09-05 egdaniel@google.com Begin renderpasses immediately in GrVkOpsRenderPass.
2019-09-05 jvanverth@google.com Add touch support to viewer
2019-09-05 michaelludwig@google.com Clean up prior backdrop-filter CL
2019-09-05 egdaniel@google.com Update some ops to create their buffers in onPrepare.
2019-09-05 ethannicholas@google.com Revert "switched SkSL interpreter over to threaded code"
2019-09-05 ethannicholas@google.com switched SkSL interpreter over to threaded code
2019-09-05 rmistry@google.com Allow PRIVATE_SKPS_GS to be empty in assets/skp/create.py

Created with:
  gclient setdep -r src/third_party/skia@172bb44f2d66

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 jlavrova@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=jlavrova@google.com

Bug: chromium:None,chromium:None,chromium:None,chromium:999682
Change-Id: I474cd2dc07896c2c1a91e4fdc9b473021e1ddb6e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1789870Reviewed-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@{#694326}

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': '6d1c0d4196f19537cc64f74bacc7d123de3be454',
+  'skia_revision': '172bb44f2d667999d768375358c3a2cbb4bbfc21',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling V8
   # and whatever else without interference from each other.