Remove origin from GrGpu::readPixels

Change-Id: I40d046c66240ab40794aa008861a1974f7f9182c
Reviewed-on: https://skia-review.googlesource.com/131620
Commit-Queue: Brian Salomon <bsalomon@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
9 files changed