Roll src/third_party/skia 28b0c5d4b3bb..2723af6a6d43 (4 commits) (#14605)

https://skia.googlesource.com/skia.git/+log/28b0c5d4b3bb..2723af6a6d43

git log 28b0c5d4b3bb..2723af6a6d43 --date=short --first-parent --format='%ad %ae %s'
2019-12-21 recipe-mega-autoroller@chops-service-accounts.iam.gserviceaccount.com Roll recipe dependencies (trivial).
2019-12-20 khushalsagar@chromium.org gpu: Disable dual source blending support on buggy driver versions.
2019-12-20 bsalomon@google.com Disable advanced blend equations on Imagination driver 1.10 and earlier
2019-12-20 robertphillips@google.com Add BC1_RGB8_UNORM support

Created with:
  gclient setdep -r src/third_party/skia@2723af6a6d43

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 borenet@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: borenet@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': '28b0c5d4b3bbb6958876b2710cc90297ff981798',
+  'skia_revision': '2723af6a6d4376289d7d541bece3c6b83352db44',
 
   # 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: 3215dfe60cf004adf931273b6db77ec7
+Signature: d0e5f176ac731a731cd8bc5d20a545f5
 
 UNUSED LICENSES: