Miscellaneous removal of GrContext usages

Change-Id: I558471002db93a09b8fd5dfa2f0929a0139295bf
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/301976
Reviewed-by: Adlai Holler <adlai@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
9 files changed