Extract the CPU code of SkGlyphRunPainter called SkGlyphRunPainterCPU

Simplify the fields used by each, and simplify the CTORs in
the original SkGlyphRunPainter.

TODO: come up with a better no gpu method. Eventually, this
should be pure Sk. There is no need for GPU to make and
serialize a slug only to draw them.

Change-Id: I446fe0c285ae778a14b30e09c8a2cff3cd1a56c1
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/538896
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Herb Derby <herb@google.com>
Auto-Submit: Herb Derby <herb@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
10 files changed