Update SkRandomScalerContext to handle mask filters.

SkRandomScalarContext would apply all path and mask filters twice, once
on the proxy and once to itself.

This also changes the SkScalerContext mask generation in anticipation of
removing the mask format overrides.

This also changes the textblobrandomfont test to fix the line spacing
and emoji handling.

Change-Id: Ib2a633d49ccb801a1849dd982185f44c1d2ea85f
Reviewed-on: https://skia-review.googlesource.com/124644
Commit-Queue: Ben Wagner <bungeman@google.com>
Reviewed-by: Jim Van Verth <jvanverth@google.com>
3 files changed