Rename GrDrawBatch->GrDrawOp

Change-Id: I18f520924b8a2548566fd61dbea4e3e12bd253dd
Reviewed-on: https://skia-review.googlesource.com/5411
Commit-Queue: Brian Salomon <bsalomon@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
78 files changed