Move the msaa dirty rect to GrRenderTargetProxy

Bug: skia:
Change-Id: I01d7932bce23dffafb86e4eb124c27420acefdd3
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/239192
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Chris Dalton <csmartdalton@google.com>
22 files changed