Roll src/third_party/skia 201b3752e642..ff4fb3335bb7 (3 commits)

https://skia.googlesource.com/skia.git/+log/201b3752e642..ff4fb3335bb7


git log 201b3752e642..ff4fb3335bb7 --date=short --no-merges --format='%ad %ae %s'
2019-04-09 ethannicholas@google.com ComposeShader GPU implementations
2019-04-09 jvanverth@google.com Add RG format to Metal
2019-04-09 mtklein@google.com extract ToolUtils::colortype_depth()


Created with:
  gclient setdep -r src/third_party/skia@ff4fb3335bb7

The AutoRoll server is located here: https://autoroll.skia.org/r/skia-autoroll

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=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=egdaniel@chromium.org

Change-Id: I8b4085d87dda9ee23a975f301e2aef2387baac23
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1560391Reviewed-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@{#649304}

DEPS

@@ -129,7 +129,7 @@ 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': '201b3752e642dfe3e66902428f7a7d0a992fddde',
+  'skia_revision': 'ff4fb3335bb79e68e71ba8ba431de1a2a0daf4e0',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling V8
   # and whatever else without interference from each other.