bd58cea90b
Closes https://github.com/dart-lang/sdk/issues/45572 getContext3d should return a nullable value since getContext can return a nullable. Change-Id: Iaefff781976656db3765d526ec95305f2acfeecf Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/194503 Reviewed-by: Sigmund Cherem <sigmund@google.com> Commit-Queue: Srujan Gaddam <srujzs@google.com>