change the way windows are parented when their parent is set to NULL.

ui/aura/window_unittest.cc

Index: ui/aura/window_unittest.cc
===================================================================
--- ui/aura/window_unittest.cc	(revision 104542)
+++ ui/aura/window_unittest.cc	(working copy)
@@ -10,6 +10,7 @@
 #include "ui/aura/event.h"
 #include "ui/aura/focus_manager.h"
 #include "ui/aura/root_window.h"
+#include "ui/aura/test_desktop_delegate.h"
 #include "ui/aura/window_delegate.h"
 #include "ui/gfx/canvas_skia.h"
 #include "ui/gfx/compositor/layer.h"
@@ -177,8 +178,6 @@
   WindowTest() : main_message_loop(MessageLoop::TYPE_UI) {
     Desktop::GetInstance()->Show();
     Desktop::GetInstance()->SetSize(gfx::Size(500, 500));
-    if (!Desktop::GetInstance()->default_parent())
-      Desktop::GetInstance()->CreateDefaultParentForTesting();
   }
   virtual ~WindowTest() {}
 
@@ -214,8 +213,14 @@
     return window;
   }
 
+ protected:
+  Window* toplevel_container() {
+    return desktop_delegate_.default_container();
+  }
+
  private:
   MessageLoop main_message_loop;
+  TestDesktopDelegate desktop_delegate_;
 
   DISALLOW_COPY_AND_ASSIGN(WindowTest);
 };
@@ -266,7 +271,7 @@
       CreateTestWindow(SK_ColorGRAY, 13, gfx::Rect(5, 470, 50, 50), w1.get()));
 
   Window* desktop = Desktop::GetInstance()->window();
-  Desktop::GetInstance()->default_parent()->SetBounds(gfx::Rect(500, 500));
+  toplevel_container()->SetBounds(gfx::Rect(500, 500));
   EXPECT_EQ(NULL, desktop->GetEventHandlerForPoint(gfx::Point(5, 5)));
   EXPECT_EQ(w1.get(), desktop->GetEventHandlerForPoint(gfx::Point(11, 11)));
   EXPECT_EQ(w11.get(), desktop->GetEventHandlerForPoint(gfx::Point(16, 16)));