Revert "Stack-allocate pipelines for GrMeshDrawOp"

This reverts commit dfe5000a5ff2cabb50ddc139882dc1f3005fa429.

Reason for revert: HWAA pipeline flag not getting set for dashing.

Original change's description:
> Stack-allocate pipelines for GrMeshDrawOp
> 
> Stack-allocates the pipelines in onExecute. This saves us from having
> to store the pipelines on the heap, as well as delaying the need to
> detach processors until onExecute. The delay is an improvement because
> it allows us to keep visiting proxies after onPrepare. (Previously,
> they were moved out of GrProcessorSet and into a pipeline during
> onPrepare, so visiting proxies was impossible after that point.)
> 
> Bug: skia:8731
> Change-Id: Idc05063fb0dfbfed42b434e429fa5a497097bdae
> Reviewed-on: https://skia-review.googlesource.com/c/193368
> Commit-Queue: Chris Dalton <csmartdalton@google.com>
> Reviewed-by: Robert Phillips <robertphillips@google.com>

TBR=robertphillips@google.com,csmartdalton@google.com

Change-Id: If706f19423310846de70288f393ac12f17ffeee5
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: skia:8731
Reviewed-on: https://skia-review.googlesource.com/c/195161
Reviewed-by: Chris Dalton <csmartdalton@google.com>
Commit-Queue: Chris Dalton <csmartdalton@google.com>
diff --git a/src/gpu/ops/GrDrawVerticesOp.cpp b/src/gpu/ops/GrDrawVerticesOp.cpp
index f1589ed..ec82f87 100644
--- a/src/gpu/ops/GrDrawVerticesOp.cpp
+++ b/src/gpu/ops/GrDrawVerticesOp.cpp
@@ -47,7 +47,6 @@
     };
 
     void onPrepareDraws(Target*) override;
-    void onExecute(GrOpFlushState*, const SkRect& chainBounds) override;
 
     void drawVolatile(Target*);
     void drawNonVolatile(Target*);
@@ -503,11 +502,8 @@
         mesh->setNonIndexedNonInstanced(fVertexCount);
     }
     mesh->setVertexData(std::move(vertexBuffer), firstVertex);
-    target->recordDraw(std::move(gp), mesh);
-}
-
-void DrawVerticesOp::onExecute(GrOpFlushState* flushState, const SkRect& chainBounds) {
-    fHelper.executeDrawsAndUploads(this, flushState, chainBounds);
+    auto pipe = fHelper.makePipeline(target);
+    target->draw(std::move(gp), pipe.fPipeline, pipe.fFixedDynamicState, mesh);
 }
 
 GrOp::CombineResult DrawVerticesOp::onCombineIfPossible(GrOp* t, const GrCaps& caps) {