Roll Skia from ba7c5258d2b4 to 56bb647a49ac (3 revisions) (flutter/engine#45118)

https://skia.googlesource.com/skia.git/+log/ba7c5258d2b4..56bb647a49ac

2023-08-25 michaelludwig@google.com [skif] Add ::Empty() convenience factory
2023-08-25 egdaniel@google.com [Graphite] Add option to set independent, custom gpu budgets on Context and Recorders.
2023-08-25 kjlubick@google.com Change defined(GR_TEST_UTILS) -> GR_TEST_UTILS

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 brianosman@google.com,jimgraham@google.com,lovisolo@google.com,rmistry@google.com on the revert to ensure that a human
is aware of the problem.

To file a bug in Skia: https://bugs.chromium.org/p/skia/issues/entry
To file a bug in Flutter: https://github.com/flutter/flutter/issues/new/choose

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/+doc/main/autoroll/README.md

DEPS

@@ -18,7 +18,7 @@ vars = {
   'llvm_git': 'https://llvm.googlesource.com',
   # OCMock is for testing only so there is no google clone
   'ocmock_git': 'https://github.com/erikdoe/ocmock.git',
-  'skia_revision': 'ba7c5258d2b4e454a8de0a44a883abe3f55bb380',
+  'skia_revision': '56bb647a49acd2a5f60689d7342ea83cebb85aeb',
 
   # WARNING: DO NOT EDIT canvaskit_cipd_instance MANUALLY
   # See `lib/web_ui/README.md` for how to roll CanvasKit to a new version.

engine/src/flutter/ci/licenses_golden/licenses_skia

@@ -1,4 +1,4 @@
-Signature: b46ad624eee632cf275544b5dad036bf
+Signature: 9919b825607c67a2cc28ac5b6174b6e6
 
 ====================================================================================================
 LIBRARY: etc1