Remove call to copy in GrcontextPriv read/write pixel calls.

Instead we just directly do all those copies as draws.

Change-Id: I0cd9dfc6f96e35fbbc9c153a28a08eebf1d7b77f
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/216356
Commit-Queue: Greg Daniel <egdaniel@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
4 files changed