Add flag to force high-precision RP

Change-Id: I9388458ae186f7b2a8b8534859147b9a1035276f
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/432016
Reviewed-by: Brian Osman <brianosman@google.com>
Reviewed-by: Herb Derby <herb@google.com>
Commit-Queue: Mike Reed <reed@google.com>
2 files changed