Roll src/third_party/skia/ 19391ac4d..21171e50f (1 commit)

https://skia.googlesource.com/skia.git/+log/19391ac4d393..21171e50f486

$ git log 19391ac4d..21171e50f --date=short --no-merges --format='%ad %ae %s'
2017-08-01 csmartdalton CCPR: Transform path points before handling curves

Created with:
  roll-dep src/third_party/skia


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

If the roll is causing failures, see:
http://www.chromium.org/developers/tree-sheriffs/sheriff-details-chromium#TOC-Failures-due-to-DEPS-rolls


CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel;master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel;master.tryserver.chromium.android:android_optional_gpu_tests_rel
TBR=liyuqian@chromium.org

Change-Id: I3e2e32dd698c500ba8a009785af887f00a6a80bb
Reviewed-on: https://chromium-review.googlesource.com/597499Reviewed-by: Skia Deps Roller <skia-deps-roller@chromium.org>
Commit-Queue: Skia Deps Roller <skia-deps-roller@chromium.org>
Cr-Commit-Position: refs/heads/master@{#491290}

DEPS

@@ -40,7 +40,7 @@ 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': '19391ac4d393874797e1d34970fecf0f0182bf98',
+  'skia_revision': '21171e50f486a7234e1d8edeb0977719c81d5d3b',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling V8
   # and whatever else without interference from each other.