Update the native_viewport interface to allow specification of the surface configuration, currently…

examples/spinning_cube/spinning_cube_app.cc

Index: examples/spinning_cube/spinning_cube_app.cc
diff --git a/examples/spinning_cube/spinning_cube_app.cc b/examples/spinning_cube/spinning_cube_app.cc
index 42e64b0b04c449da97fcb437d07489dfac6c2b4c..dc51990a8c56459a6bf85dcb1b38890cc455426b 100644
--- a/examples/spinning_cube/spinning_cube_app.cc
+++ b/examples/spinning_cube/spinning_cube_app.cc
@@ -41,8 +41,12 @@ class SpinningCubeApp : public mojo::ApplicationDelegate,
     mojo::SizePtr size(mojo::Size::New());
     size->width = 800;
     size->height = 600;
+
+    auto requested_configuration = mojo::SurfaceConfiguration::New();
+    requested_configuration->depth_bits = 16;
+
     viewport_->Create(
-        size.Clone(),
+        size.Clone(), requested_configuration.Pass(),
         base::Bind(&SpinningCubeApp::OnMetricsChanged, base::Unretained(this)));
     viewport_->Show();
     mojo::ContextProviderPtr onscreen_context_provider;