Changes views_aura_mus_unittests to create DesktopNativeWidgetAura

ui/views/test/views_test_base.h

Index: ui/views/test/views_test_base.h
diff --git a/ui/views/test/views_test_base.h b/ui/views/test/views_test_base.h
index 1b7d171903b2dd09f1609b8c46a27283d47db903..74cfb8ea06fdf60ff023c057648f0022e6b4416e 100644
--- a/ui/views/test/views_test_base.h
+++ b/ui/views/test/views_test_base.h
@@ -48,6 +48,9 @@ class ViewsTestBase : public PlatformTest {
 
   bool HasCompositingManager() const;
 
+  // Simulate an OS-level destruction of the native window held by |widget|.
+  void SimulateNativeDestroy(Widget* widget);
+
  protected:
   TestViewsDelegate* views_delegate() const {
     return test_helper_->views_delegate();