Add wrapBackendTextureAsRenderTarget API

src/image/SkSurface.cpp

Index: src/image/SkSurface.cpp
diff --git a/src/image/SkSurface.cpp b/src/image/SkSurface.cpp
index fed13a284beaed2202f5d2bde92f71032dcc777f..34b39db262eb936b4c4c278bc624c0d02a1cb7cf 100644
--- a/src/image/SkSurface.cpp
+++ b/src/image/SkSurface.cpp
@@ -195,6 +195,10 @@ bool SkSurface::getRenderTargetHandle(GrBackendObject* obj, BackendHandleAccess
     return asSB(this)->onGetRenderTargetHandle(obj, access);
 }
 
+void SkSurface::prepareForExternalIO() {
+  asSB(this)->onPrepareForExternalIO();
+}
+
 //////////////////////////////////////////////////////////////////////////////////////
 
 #if !SK_SUPPORT_GPU
@@ -218,4 +222,9 @@ SkSurface* SkSurface::NewFromBackendRenderTarget(GrContext*, const GrBackendRend
     return nullptr;
 }
 
+SkSurface* NewFromBackendTextureAsRenderTarget(GrContext*, const GrBackendTextureDesc&,
+                                               const SkSurfaceProps*) {
+    return nullptr;
+}
+
 #endif