Keep dedicated layers for hiding animation

ui/wm/core/focus_controller.cc

Index: ui/wm/core/focus_controller.cc
diff --git a/ui/wm/core/focus_controller.cc b/ui/wm/core/focus_controller.cc
index c4e67cf6d072debd8da28adb34fb598b7de1ed4e..38e8920b47a33db849221747001e76099681cadf 100644
--- a/ui/wm/core/focus_controller.cc
+++ b/ui/wm/core/focus_controller.cc
@@ -32,24 +32,6 @@ void StackTransientParentsBelowModalWindow(aura::Window* window) {
   }
 }
 
-// Stack's |window|'s layer above |relative_to|'s layer.
-void StackWindowLayerAbove(aura::Window* window, aura::Window* relative_to) {
-  // Stack |window| above the last transient child of |relative_to| that shares
-  // the same parent.
-  const aura::Window::Windows& window_transients(
-      GetTransientChildren(relative_to));
-  for (aura::Window::Windows::const_iterator i = window_transients.begin();
-       i != window_transients.end(); ++i) {
-    aura::Window* transient = *i;
-    if (transient->parent() == relative_to->parent())
-      relative_to = transient;
-  }
-  if (window != relative_to) {
-    window->layer()->parent()->StackAbove(window->layer(),
-                                          relative_to->layer());
-  }
-}
-
 }  // namespace
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -208,14 +190,8 @@ void FocusController::OnGestureEvent(ui::GestureEvent* event) {
 
 void FocusController::OnWindowVisibilityChanged(aura::Window* window,
                                                 bool visible) {
-  if (!visible) {
+  if (!visible)
     WindowLostFocusFromDispositionChange(window, window->parent());
-    // Despite the focus change, we need to keep the window being hidden
-    // stacked above the new window so it stays open on top as it animates away.
-    aura::Window* next_window = GetActiveWindow();
-    if (next_window && next_window->parent() == window->parent())
-      StackWindowLayerAbove(window, next_window);
-  }
 }
 
 void FocusController::OnWindowDestroying(aura::Window* window) {