Begin instanced rendering for simple shapes

src/gpu/GrDrawContextPriv.h

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrDrawContextPriv_DEFINED
 #define GrDrawContextPriv_DEFINED
 
 #include "GrDrawContext.h"
+#include "GrDrawTarget.h"
 #include "GrPathRendering.h"
 
 class GrFixedClip;
 class GrPath;
 struct GrUserStencilSettings;
 
 /** Class that adds methods to GrDrawContext that are only intended for use internal to Skia.
     This class is purely a privileged window into GrDrawContext. It should never have additional
     data members or virtual methods. */
 class GrDrawContextPriv {
 public:
+    gr_instanced::InstancedRendering* accessInstancedRendering() const {
+        return fDrawContext->getDrawTarget()->instancedRendering();
+    }
+
     void clearStencilClip(const SkIRect& rect, bool insideClip);
 
     void stencilRect(const GrFixedClip& clip,
                      const GrUserStencilSettings* ss,
                      bool useHWAA,
                      const SkMatrix& viewMatrix,
                      const SkRect& rect);
 
     void stencilPath(const GrPipelineBuilder&,
                      const GrClip&,
@@ skipping 36 matching lines @@
     friend class GrDrawContext; // to construct/copy this type.
 };
 
 inline GrDrawContextPriv GrDrawContext::drawContextPriv() { return GrDrawContextPriv(this); }
 
 inline const GrDrawContextPriv GrDrawContext::drawContextPriv () const {
     return GrDrawContextPriv(const_cast<GrDrawContext*>(this));
 }
 
 #endif