add old fix for iOS SampleApp

experimental/iOSSampleApp/SkSampleUIView.mm

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #import "SkSampleUIView.h"
 
 //#define SKGL_CONFIG         kEAGLColorFormatRGB565
@@ skipping 143 matching lines @@
             glBindFramebuffer(GL_FRAMEBUFFER, fLayerFBO);
             GrBackendRenderTargetDesc desc;
             desc.fWidth = SkScalarRoundToInt(win->width());
             desc.fHeight = SkScalarRoundToInt(win->height());
             desc.fConfig = kSkia8888_GrPixelConfig;
             desc.fRenderTargetHandle = fLayerFBO;
             desc.fSampleCnt = info.fSampleCount;
             desc.fStencilBits = info.fStencilBits;
 
             SkSafeUnref(fCurRenderTarget);
-            fCurRenderTarget = fCurContext->wrapBackendRenderTarget(desc);
+            fCurRenderTarget = fCurContext->textureProvider()->wrapBackendRenderTarget(desc);
         }
 #endif
     }
     
     GrContext* getGrContext() override {
 #if SK_SUPPORT_GPU
         return fCurContext;
 #else
         return NULL;
 #endif
@@ skipping 296 matching lines @@
     glBindRenderbuffer(GL_RENDERBUFFER, fGL.fRenderbuffer);
     glGetRenderbufferParameteriv(GL_RENDERBUFFER,
                                  GL_RENDERBUFFER_STENCIL_SIZE,
                                  &info->fStencilBits);
     glGetRenderbufferParameteriv(GL_RENDERBUFFER,
                                  GL_RENDERBUFFER_SAMPLES_APPLE,
                                  &info->fSampleCount);
 }
 
 @end