aura: Reland r266681 to debug WindowObserver crashes.

ui/aura/window_unittest.cc

Index: ui/aura/window_unittest.cc
diff --git a/ui/aura/window_unittest.cc b/ui/aura/window_unittest.cc
index 5e08a170da097f9d34b11acccb75a0bce6ed295e..add99d43483152bc8ca921e503649e9e6eb50bb0 100644
--- a/ui/aura/window_unittest.cc
+++ b/ui/aura/window_unittest.cc
@@ -2229,6 +2229,7 @@ TEST_F(WindowTest, RootWindowSetWhenReparenting) {
   parent1.SetBounds(gfx::Rect(10, 10, 300, 300));
   parent2.SetBounds(gfx::Rect(20, 20, 300, 300));
 
+  BoundsChangedWindowObserver observer;
   Window child(NULL);
   child.Init(aura::WINDOW_LAYER_NOT_DRAWN);
   child.SetBounds(gfx::Rect(5, 5, 100, 100));
@@ -2242,7 +2243,6 @@ TEST_F(WindowTest, RootWindowSetWhenReparenting) {
   gfx::Rect new_bounds(gfx::Rect(35, 35, 50, 50));
   child.SetBounds(new_bounds);
 
-  BoundsChangedWindowObserver observer;
   child.AddObserver(&observer);
 
   // Reparenting the |child| will cause it to get moved. During this move