Remove more GrContext imports & usage

Sanity is coming soon!

Change-Id: I109ebeef9efd7dbf4d76a13e1c05df36d59affbc
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/303661
Commit-Queue: Adlai Holler <adlai@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
41 files changed