Add wrapBackendTextureAsRenderTarget API

src/image/SkSurface.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkSurface_Base.h"
 #include "SkImagePriv.h"
 #include "SkCanvas.h"
@@ skipping 177 matching lines @@
 }
 
 GrBackendObject SkSurface::getTextureHandle(BackendHandleAccess access) {
     return asSB(this)->onGetTextureHandle(access);
 }
 
 bool SkSurface::getRenderTargetHandle(GrBackendObject* obj, BackendHandleAccess access) {
     return asSB(this)->onGetRenderTargetHandle(obj, access);
 }
 
+void SkSurface::prepareForExternalIO() {
+  asSB(this)->onPrepareForExternalIO();
+}
+
 //////////////////////////////////////////////////////////////////////////////////////
 
 #if !SK_SUPPORT_GPU
 
 SkSurface* SkSurface::NewRenderTargetDirect(GrRenderTarget*, const SkSurfaceProps*) {
     return nullptr;
 }
 
 SkSurface* SkSurface::NewRenderTarget(GrContext*, Budgeted, const SkImageInfo&, int,
                                       const SkSurfaceProps*, GrTextureStorageAllocator) {
     return nullptr;
 }
 
 SkSurface* SkSurface::NewFromBackendTexture(GrContext*, const GrBackendTextureDesc&,
                                              const SkSurfaceProps*) {
     return nullptr;
 }
 
 SkSurface* SkSurface::NewFromBackendRenderTarget(GrContext*, const GrBackendRenderTargetDesc&,
                                                  const SkSurfaceProps*) {
     return nullptr;
 }
 
+SkSurface* NewFromBackendTextureAsRenderTarget(GrContext*, const GrBackendTextureDesc&,
+                                               const SkSurfaceProps*) {
+    return nullptr;
+}
+
 #endif