Separate cache lookup from run font setup

Seperate concerns so that cache lookup and run setup are different code.
This will allow the common code in painter to do the caache lookup.

Change-Id: I30a208ebc715c07f5720a7a8fc8240aabfda869d
Reviewed-on: https://skia-review.googlesource.com/c/180928
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Herb Derby <herb@google.com>
3 files changed