add API for Op creation

Introduce three calls on GrOp: Make, MakeWithExtraMemory,
and MakeWithProcessorSet. Instead of returning
unique_ptr<GrOp>, they return a type of GrOp::OpOwner.
GrOp::OpOwner safely deletes the op when it goes out
of scope for either new/delete or GrOpMemoryPool
allocations.

In order to make the code easier to refactor, I
eliminated MakeArg from the helpers.

Change-Id: Icfd697906f3147a8734575d08bd7195e7517383a
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/323778
Reviewed-by: Michael Ludwig <michaelludwig@google.com>
Commit-Queue: Herb Derby <herb@google.com>
diff --git a/src/gpu/ops/GrSimpleMeshDrawOpHelper.cpp b/src/gpu/ops/GrSimpleMeshDrawOpHelper.cpp
index 23bc438..d52f51e 100644
--- a/src/gpu/ops/GrSimpleMeshDrawOpHelper.cpp
+++ b/src/gpu/ops/GrSimpleMeshDrawOpHelper.cpp
@@ -13,10 +13,10 @@
 #include "src/gpu/geometry/GrRect.h"
 #include "src/gpu/ops/GrSimpleMeshDrawOpHelper.h"
 
-GrSimpleMeshDrawOpHelper::GrSimpleMeshDrawOpHelper(const MakeArgs& args,
+GrSimpleMeshDrawOpHelper::GrSimpleMeshDrawOpHelper(GrProcessorSet* processorSet,
                                                    GrAAType aaType,
                                                    InputFlags inputFlags)
-        : fProcessors(args.fProcessorSet)
+        : fProcessors(processorSet)
         , fPipelineFlags((GrPipeline::InputFlags)inputFlags)
         , fAAType((int)aaType)
         , fUsesLocalCoords(false)