Add test configs for instanced rendering

src/gpu/GrGpu.h

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrGpu_DEFINED
 #define GrGpu_DEFINED
 
@@ skipping 134 matching lines @@
      * @param data            optional data with which to initialize the buffer.
      *
      * @return the buffer if successful, otherwise nullptr.
      */
     GrBuffer* createBuffer(size_t size, GrBufferType intendedType, GrAccessPattern accessPattern,
                            const void* data = nullptr);
 
     /**
      * Creates an instanced rendering object if it is supported on this platform.
      */
-    virtual gr_instanced::InstancedRendering* createInstancedRenderingIfSupported() {
-        return nullptr;
-    }
+    gr_instanced::InstancedRendering* createInstancedRendering();
 
     /**
      * Resolves MSAA.
      */
     void resolveRenderTarget(GrRenderTarget* target);
 
     /** Info struct returned by getReadPixelsInfo about performing intermediate draws before
         reading pixels for performance or correctness. */
     struct ReadPixelTempDrawInfo {
         /** If the GrGpu is requesting that the caller do a draw to an intermediate surface then
@@ skipping 362 matching lines @@
                                                  SkBudgeted budgeted,
                                                  const SkTArray<GrMipLevel>& texels) = 0;
 
     virtual GrTexture* onWrapBackendTexture(const GrBackendTextureDesc&, GrWrapOwnership) = 0;
     virtual GrRenderTarget* onWrapBackendRenderTarget(const GrBackendRenderTargetDesc&,
                                                       GrWrapOwnership) = 0;
     virtual GrRenderTarget* onWrapBackendTextureAsRenderTarget(const GrBackendTextureDesc&) = 0;
     virtual GrBuffer* onCreateBuffer(size_t size, GrBufferType intendedType, GrAccessPattern,
                                      const void* data) = 0;
 
+    virtual gr_instanced::InstancedRendering* onCreateInstancedRendering() = 0;
+
     virtual bool onMakeCopyForTextureParams(GrTexture* texture, const GrTextureParams&,
                                             GrTextureProducer::CopyParams*) const { return false; }
 
     virtual bool onGetReadPixelsInfo(GrSurface* srcSurface, int readWidth, int readHeight,
                                      size_t rowBytes, GrPixelConfig readConfig, DrawPreference*,
                                      ReadPixelTempDrawInfo*) = 0;
     virtual bool onGetWritePixelsInfo(GrSurface* dstSurface, int width, int height,
                                       GrPixelConfig srcConfig, DrawPreference*,
                                       WritePixelTempDrawInfo*) = 0;
 
@@ skipping 48 matching lines @@
     SkSTArray<1, MultisampleSpecs, true>   fMultisampleSpecs;
     // The context owns us, not vice-versa, so this ptr is not ref'ed by Gpu.
     GrContext*                             fContext;
 
     friend class GrPathRendering;
     friend class gr_instanced::InstancedRendering;
     typedef SkRefCnt INHERITED;
 };
 
 #endif