Call ShowRootWindow on NativeWindow's RootWindow to display the window.

content/shell/minimal_ash.h

Index: content/shell/minimal_ash.h
diff --git a/content/shell/minimal_ash.h b/content/shell/minimal_ash.h
index f3ec43b4067e5ec35fa84477e85629dcb28f2354..a4178917d3b9f5fdb4aa22451db00a8e90f18675 100644
--- a/content/shell/minimal_ash.h
+++ b/content/shell/minimal_ash.h
@@ -23,6 +23,7 @@ class TestActivationClient;
 
 namespace gfx {
 class Rect;
+class Size;
 }
 
 namespace views {
@@ -39,7 +40,7 @@ namespace content {
 // the ash parts of the code.
 class MinimalAsh : public aura::client::StackingClient {
  public:
-  MinimalAsh();
+  explicit MinimalAsh(const gfx::Size& default_window_size);
   virtual ~MinimalAsh();
 
   // Overridden from client::StackingClient: