Prevent crash when flushing while DDL recording

Change-Id: I35e96d3c3020092b33d9b952394d40d4fd5a587b
Reviewed-on: https://skia-review.googlesource.com/114685
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
2 files changed