Retract PipelineBuilder some more

The main part of this CL is widening SkDrawContext::drawBatch's API to accept the userStencilSettings & drawFace

There is some ancillary spookiness related to expanding the should_apply_coverage_aa & mustUseHWAA methods to encompass mixedSamples

Calved off:
https://codereview.chromium.org/2165283002/ (Remove DrawFace enum from GrPipelineBuilder)
https://codereview.chromium.org/2167183002/ (Minor change to Ganesh path renderers)

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2092893003

Review-Url: https://codereview.chromium.org/2092893003
16 files changed