Roll src/third_party/skia 4af17e434cdc..78b471760dd9 (1 commits) (#16660)

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': '4af17e434cdc9b0eeb63e0596424c664ca3b4565',
+  'skia_revision': '78b471760dd9aedc01177e8bb81226d298a1dcea',
 
   # When updating the Dart revision, ensure that all entries that are
   # dependencies of Dart are also updated to match the entries in the