Split out SkRunFont and SkPaint

Coping paints take significant time. The ApplyFontToPaint
idiom requires a copy and a dtor. This CL keeps the paint and
font in parallel through the code until a paint is actually
needed, then a special ctor is used to create it.

Also, inline a bunch of text blob calls that were showing up
in perf.

Change-Id: I7da746a287e4d3942e45e9536ef9acdc64f084d4
Reviewed-on: https://skia-review.googlesource.com/c/159222
Reviewed-by: Mike Klein <mtklein@google.com>
Reviewed-by: Herb Derby <herb@google.com>
Commit-Queue: Herb Derby <herb@google.com>
7 files changed