Rename GrBatchFlushState to GrOpFlushState

Change-Id: I1a8052c61d7624929caf45ba44e2a465cd0dc1c2
Reviewed-on: https://skia-review.googlesource.com/5649
Commit-Queue: Brian Salomon <bsalomon@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
54 files changed