Rename batch->op and sk_sp in instanced rendering

Change-Id: I9df450f2bce51d4f803d419bef863ca3a3314f09
Reviewed-on: https://skia-review.googlesource.com/6162
Commit-Queue: Brian Salomon <bsalomon@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
8 files changed