Sketch SkPictureRecorder::optimizeFor(GrContext*).

I'm open to API suggestions.
We can pass this in finishAs(), up front, whatever.

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2203453002

Review-Url: https://codereview.chromium.org/2203453002
4 files changed