Use Analytic AA in SkAAClip.

Use Analytic AA in SkAAClip.

This will fix some Chrome ref tests.

The main issue here is that the SkAAClip requires: (1) we blit in order, and (2) we must forceRLE.

Note that this still depends on the global gSkUseAnalyticAA to turn on the Analytic AA.

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2430343003

Review-Url: https://chromiumcodereview.appspot.com/2430343003