We still occasionally downcast, so this is not airtight,
but it (1) allows us to know where we are downcasting and
(2) lets us move away from GrContext (and hopefully remove
it sooner than later.)
All three canaries are currently broken =( so here we go!
Bug: skia:104662
Change-Id: I84efe132574690b62ea512e194e4f9e318e9c050
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/316218
Commit-Queue: Adlai Holler <adlai@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
302e8fb771