Move instanced index buffer creation to flush time

include/gpu/GrTextureProvider.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrTextureProvider_DEFINED
 #define GrTextureProvider_DEFINED
 
@@ skipping 136 matching lines @@
      */
     bool existsResourceWithUniqueKey(const GrUniqueKey& key) const;
 
     GrTexture* internalRefScratchTexture(const GrSurfaceDesc&, uint32_t flags);
 
     void abandon() {
         fCache = NULL;
         fGpu = NULL;
     }
 
+    GrResourceCache* cache() { return fCache; }
+    const GrResourceCache* cache() const { return fCache; }
+
+    GrGpu* gpu() { return fGpu; }
+    const GrGpu* gpu() const { return fGpu; }
+
 private:
     bool isAbandoned() const {
         SkASSERT(SkToBool(fGpu) == SkToBool(fCache));
         return !SkToBool(fCache);
     }
 
     GrResourceCache* fCache;
     GrGpu* fGpu;
 };
 
 #endif