Remove GrPipeline from GrDrawOp.

GrDrawOp subclasses are now free to construct their pipelines at flush time and now in theory could use multiple GrPipelines for multipass rendering.

GrProcessorSet may be used to retain the processors from a GrPaint with "pending execution" style refs.

NVPR and Instanced rendering are updated to create their pipelines at flush time without a GrPipelineBuilder.

The monolithic pipeline creation/management that was on GrDrawOp is moved to GrMeshDrawOp. However, this is temporary and will be removed in coming changes.

Change-Id: I124282e3cea5d070970b5460c8a679fcaf7a8eff
Reviewed-on: https://skia-review.googlesource.com/7279
Commit-Queue: Brian Salomon <bsalomon@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
34 files changed