Remove uses of the glyph cache

Because the empty checks have been hoisted to the common code,
glyph cache is not needed by the painter closures.

Unify on the name textScale for all the code.

Capture run pointers by value.

Change-Id: I18be54fce7f52f336ae293d8897544393faca125
Reviewed-on: https://skia-review.googlesource.com/c/173645
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Herb Derby <herb@google.com>
3 files changed