Roll src/third_party/skia/ 489530e06..d170c0fb4 (3 commits)

https://skia.googlesource.com/skia.git/+log/489530e06cb7..d170c0fb48aa

$ git log 489530e06..d170c0fb4 --date=short --no-merges --format='%ad %ae %s'
2017-05-01 msarett Only store width and height on SkPixelRef (last part)
2017-05-01 msarett Blacklist testimgari.jpg on CG
2017-05-01 fmalita Restore legacy SaveLayerRec ctor

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=scroggo@chromium.org

Change-Id: I4032fc211df6523e4a410f5c947af654083cb45c
Reviewed-on: https://chromium-review.googlesource.com/491248Reviewed-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@{#468404}

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': '489530e06cb7dde13db1271dbf55452d79cd119d',
+  'skia_revision': 'd170c0fb48aa1e1a00d183d72f9e53ea9bb4d951',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling V8
   # and whatever else without interference from each other.