Bug fixes for Flutter

Change-Id: Ic71e377290acc8a1b4cf62c52b3cc760c31dbb3b
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/235802
Reviewed-by: Ben Wagner <bungeman@google.com>
Commit-Queue: Julia Lavrova <jlavrova@google.com>
6 files changed