Removes most of aura dependencies from DefaultState

ash/wm/common/window_parenting_utils.cc

Index: ash/wm/common/window_parenting_utils.cc
diff --git a/ash/wm/common/window_parenting_utils.cc b/ash/wm/common/window_parenting_utils.cc
new file mode 100644
index 0000000000000000000000000000000000000000..1e31fc4417ab261a5bc2a101686bd13ec0ee6e36
--- /dev/null
+++ b/ash/wm/common/window_parenting_utils.cc
@@ -0,0 +1,28 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ash/wm/common/window_parenting_utils.h"
+
+#include "ash/wm/common/wm_window.h"
+
+namespace ash {
+namespace wm {
+
+void ReparentChildWithTransientChildren(WmWindow* child,
+                                        WmWindow* old_parent,
+                                        WmWindow* new_parent) {
+  if (child->GetParent() == old_parent)
+    new_parent->AddChild(child);
+  ReparentTransientChildrenOfChild(child, old_parent, new_parent);
+}
+
+void ReparentTransientChildrenOfChild(WmWindow* child,
+                                      WmWindow* old_parent,
+                                      WmWindow* new_parent) {
+  for (WmWindow* transient_child : child->GetTransientChildren())
+    ReparentChildWithTransientChildren(transient_child, old_parent, new_parent);
+}
+
+}  // namespace wm
+}  // namespace ash