8ee26d8a19
This allows creating strong mode TypeEnvironments without actually subclassing it. Make SubtypeTester.isBottom treat Null as Bottom in strong mode. Bug: Change-Id: Icdd1a4b736ce0fe839a6ef30cf24487111f32d25 Reviewed-on: https://dart-review.googlesource.com/11882 Reviewed-by: Paul Berry <paulberry@google.com>