Cleanup use of legacy SkSurface creation methods a bit

experimental/GLFWTest/glfw_main.cpp

Index: experimental/GLFWTest/glfw_main.cpp
diff --git a/experimental/GLFWTest/glfw_main.cpp b/experimental/GLFWTest/glfw_main.cpp
index a8ca7ea97e8f731df56f98271f7bed367c0a56df..21ec33def3c7ba7c2f26b6ecf87a4f2980955671 100644
--- a/experimental/GLFWTest/glfw_main.cpp
+++ b/experimental/GLFWTest/glfw_main.cpp
@@ -42,7 +42,7 @@ static void init_skia(int w, int h) {
     desc.fStencilBits = 0;
     desc.fRenderTargetHandle = 0;  // assume default framebuffer
  
-    sSurface = SkSurface::NewFromBackendRenderTarget(sContext, desc, NULL);
+    sSurface = SkSurface::MakeFromBackendRenderTarget(sContext, desc, nullptr, nullptr).release();
 }
 
 static void cleanup_skia() {