Delete SkPixelRef::readPixels()

Nobody calls this or overrides this.

Bug: skia:
Change-Id: I6235e4c7bcdc45523ce7f63842635c79e00d2dc4
Reviewed-on: https://skia-review.googlesource.com/11357
Commit-Queue: Matt Sarett <msarett@google.com>
Reviewed-by: Mike Reed <reed@google.com>
3 files changed