Currently this is possible by getting the canvas off of surface and then
getting the context off of the canvas. However, if in the future we wanted
a surface that didn't have a canvas (maybe something that looked like a
mutible image that only had a writePixels call), this would allow us to
still get the GrContext.
Bug: skia:10118
Change-Id: Ie8504bb708c1e4532edc8c7832ead86ae711e237
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/289479
Commit-Queue: Greg Daniel <egdaniel@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
5ab94e1ae6