switch surface to sk_sp

example/HelloWorld.h

Index: example/HelloWorld.h
diff --git a/example/HelloWorld.h b/example/HelloWorld.h
index ef4e417ad62b60b5a93b1ed6f2f80955f8bb02a5..619ee7cb4df317b32014f049bcad3924d9e5a376 100644
--- a/example/HelloWorld.h
+++ b/example/HelloWorld.h
@@ -36,11 +36,11 @@ protected:
     SkSurface* createSurface() override {
         SkSurfaceProps props(INHERITED::getSurfaceProps());
         if (kGPU_DeviceType == fType) {
-            return SkSurface::NewRenderTargetDirect(fRenderTarget, &props);
+            return SkSurface::MakeRenderTargetDirect(fRenderTarget, &props).release();
         }
         static const SkImageInfo info = SkImageInfo::MakeN32Premul(
                 SkScalarRoundToInt(this->width()), SkScalarRoundToInt(this->height()));
-        return fSurface = SkSurface::NewRaster(info, &props);
+        return fSurface = SkSurface::MakeRaster(info, &props).release();
     }
 
     void draw(SkCanvas* canvas) override;