db173bf585
Remove special case for null in message snapshots; snapshots are sometimes read or written with no current isolate group. Currently still all copies pointing into the VM isolate. TEST=ci Change-Id: I6fa47b2c04b0abaae74210c86f9fdf17ec932db7 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/493222 Reviewed-by: Alexander Aprelev <aam@google.com> Commit-Queue: Ryan Macnak <rmacnak@google.com>