Check for valid input to text draw.

Bug: oss-fuzz:8821
Change-Id: I170b64f97cd7189f8dbe3982b8dcc47afcb14cde
Reviewed-on: https://skia-review.googlesource.com/155940
Commit-Queue: Jim Van Verth <jvanverth@google.com>
Reviewed-by: Herb Derby <herb@google.com>
1 file changed