Roll src/third_party/skia 043dba039e0d..cf4deab60e30 (5 commits) (#12278)

https://skia.googlesource.com/skia.git/+log/043dba039e0d..cf4deab60e30

git log 043dba039e0d..cf4deab60e30 --date=short --no-merges --format='%ad %ae %s'
2019-09-13 ethannicholas@google.com Improved skslc depth tracking
2019-09-13 michaelludwig@google.com Always create an approx-size texture for approx-fit proxies
2019-09-13 ethannicholas@google.com SkSL now supports constant 1/0 in all swizzle channels, as well as "LTRB" as an alias for "xyzw" / "rgba".
2019-09-13 recipe-mega-autoroller@chops-service-accounts.iam.gserviceaccount.com Roll recipe dependencies (trivial).
2019-09-13 mtklein@google.com test we already have SkPicture::drawsNothing()

Created with:
  gclient setdep -r src/third_party/skia@cf4deab60e30

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/skia-flutter-autoroll
Please CC mtklein@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

Bug: None
TBR=mtklein@google.com

DEPS

@@ -26,7 +26,7 @@ vars = {
   'skia_git': 'https://skia.googlesource.com',
   # OCMock is for testing only so there is no google clone
   'ocmock_git': 'https://github.com/erikdoe/ocmock.git',
-  'skia_revision': '043dba039e0d29fd838fd9eab74d1f94866b7afb',
+  'skia_revision': 'cf4deab60e30532c4a463ee1827ddd4833fec879',
 
   # When updating the Dart revision, ensure that all entries that are
   # dependencies of Dart are also updated to match the entries in the

ci/licenses_golden/licenses_skia

-Signature: 6a71de06e2ce0d5e8fccb1b30ab1f7a0
+Signature: 58cac6336d21acafce04212f538c6e7f
 
 UNUSED LICENSES: