more simple makers for textblobs

To aid in the transition away from drawText, drawPosText, etc.
... see https://skia-review.googlesource.com/c/skia/+/175240

Definitely need to have a follow-on discussion about tradeoffs for the
various positioning backends.

Bug: skia:
Change-Id: I236e151f6604d868dc18f98503c371f41593ec6e
Reviewed-on: https://skia-review.googlesource.com/c/175248
Commit-Queue: Mike Reed <reed@google.com>
Reviewed-by: Florin Malita <fmalita@chromium.org>
4 files changed