Add test configs for instanced rendering

src/gpu/instanced/GLInstancedRendering.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 gr_instanced_GLInstancedRendering_DEFINED
 #define gr_instanced_GLInstancedRendering_DEFINED
 
+#include "GrCaps.h"
 #include "gl/GrGLBuffer.h"
 #include "instanced/InstancedRendering.h"
 
+class GrGLCaps;
 class GrGLGpu;
 
 #define GR_GL_LOG_INSTANCED_BATCHES 0
 
 namespace gr_instanced {
 
 class GLInstancedRendering final : public InstancedRendering {
 public:
-    static GLInstancedRendering* CreateIfSupported(GrGLGpu*);
+    GLInstancedRendering(GrGLGpu*);
     ~GLInstancedRendering() override;
 
 private:
-    GLInstancedRendering(GrGLGpu*, AntialiasMode lastSupportedAAMode);
+    /**
+     * Called by GrGLCaps to determine the level of support this class can offer for instanced
+     * rendering on the current platform.
+     */
+    static GrCaps::InstancedSupport CheckSupport(const GrGLCaps&);
 
     GrGLGpu* glGpu() const;
 
     Batch* createBatch() override;
 
     void onBeginFlush(GrResourceProvider*) override;
     void onDraw(const GrPipeline&, const InstanceProcessor&, const Batch*) override;
     void onEndFlush() override;
     void onResetGpuResources(ResetType) override;
 
     void flushInstanceAttribs(int baseInstance);
 
     struct GLDrawCmdInfo {
         int fInstanceCount;
 #if GR_GL_LOG_INSTANCED_BATCHES
         IndexRange fGeometry;
 #endif
     };
 
     GrGLuint                              fVertexArrayID;
     SkAutoTUnref<GrBuffer>                fInstanceBuffer;
     SkAutoTUnref<GrBuffer>                fDrawIndirectBuffer;
     SkAutoSTMalloc<1024, GLDrawCmdInfo>   fGLDrawCmdsInfo;
     uint32_t                              fInstanceAttribsBufferUniqueId;
     int                                   fInstanceAttribsBaseInstance;
 
     class GLBatch;
 
+    friend class ::GrGLCaps; // For CheckSupport.
+
     typedef InstancedRendering INHERITED;
 };
 
 }
 
 #endif