Roll Dart SDK from aaab579579be to 42a0bf548ea3 (1 revision) (flutter#21946)

Author: skia-flutter-autoroll

DEPS

@@ -34,7 +34,7 @@ vars = {
   # Dart is: https://github.com/dart-lang/sdk/blob/master/DEPS.
   # You can use //tools/dart/create_updated_flutter_deps.py to produce
   # updated revision list of existing dependencies.
-  'dart_revision': 'aaab579579bedd316956bec2e0853c4ad3c3fbb2',
+  'dart_revision': '42a0bf548ea3a2d2c3926f357333d771c7bbe8cd',
 
   # WARNING: DO NOT EDIT MANUALLY
   # The lines between blank lines above and below are generated by a script. See create_updated_flutter_deps.py
@@ -235,7 +235,7 @@ deps = {
    Var('dart_git') + '/logging.git@1590ba0b648a51e7eb3895c612e4b72f72623b6f',
 
   'src/third_party/dart/third_party/pkg/markdown':
-   Var('dart_git') + '/markdown.git@dbeafd47759e7dd0a167602153bb9c49fb5e5fe7',
+   Var('dart_git') + '/markdown.git@6f89681d59541ddb1cf3a58efbdaa2304ffc3f51',
 
   'src/third_party/dart/third_party/pkg/matcher':
    Var('dart_git') + '/matcher.git@9cae8faa7868bf3a88a7ba45eb0bd128e66ac515',

ci/licenses_golden/licenses_third_party

@@ -1,4 +1,4 @@
-Signature: 32290c22f0ebd5322802b8512a00e00e
+Signature: 2bb9dcb314a53c20072e7759afee8c18
 
 UNUSED LICENSES: