Roll Dart SDK from 04f4272546af to e87cb96bb89c (7 revisions) (flutter#20152)

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': '04f4272546afab35c0a0c55cd3a049f7d61eb941',
+  'dart_revision': 'e87cb96bb89cdba1c57358921894626cb21de7c5',
 
   # WARNING: DO NOT EDIT MANUALLY
   # The lines between blank lines above and below are generated by a script. See create_updated_flutter_deps.py