[graphite] Cache read view on DrawContext

readSurfaceView() no longer requires a Caps, so it opens up the
possibility for Device to abandon its recorder and still be used as
a texture source.

Bug: b/323887207
Change-Id: I2db067804be32ef701d57e2a890b4163829c9186
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/835179
Reviewed-by: Jim Van Verth <jvanverth@google.com>
Commit-Queue: Michael Ludwig <michaelludwig@google.com>
3 files changed