Make AA hairline renderer non-optional

Change-Id: I0d4166a4e9ea894f479755f9f7137c5941cf8a22
Reviewed-on: https://skia-review.googlesource.com/41081
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
3 files changed