Removes most of aura dependencies from DefaultState

ash/wm/panels/panel_window_resizer.cc

Index: ash/wm/panels/panel_window_resizer.cc
diff --git a/ash/wm/panels/panel_window_resizer.cc b/ash/wm/panels/panel_window_resizer.cc
index b5c44bc162c1166c482cd37ae0a41c1e84a1fbff..987c0c74a1fd9fca655763e1f927158318dc22c0 100644
--- a/ash/wm/panels/panel_window_resizer.cc
+++ b/ash/wm/panels/panel_window_resizer.cc
@@ -11,6 +11,7 @@
 #include "ash/shelf/shelf_widget.h"
 #include "ash/shell.h"
 #include "ash/shell_window_ids.h"
+#include "ash/wm/common/window_parenting_utils.h"
 #include "ash/wm/panels/panel_layout_manager.h"
 #include "ash/wm/window_state.h"
 #include "ash/wm/window_util.h"
@@ -181,7 +182,10 @@ void PanelWindowResizer::StartedDragging() {
     aura::Window* old_parent = target->parent();
     aura::client::ParentWindowWithContext(
         target, target_root, target_root->GetBoundsInScreen());
-    wm::ReparentTransientChildrenOfChild(target, old_parent, target->parent());
+    ash::wm::ReparentTransientChildrenOfChild(
+        ash::wm::WmWindowAura::Get(target),
+        ash::wm::WmWindowAura::Get(old_parent),
+        ash::wm::WmWindowAura::Get(target->parent()));
   }
 }
 
@@ -197,7 +201,10 @@ void PanelWindowResizer::FinishDragging() {
     aura::Window* old_parent = target->parent();
     aura::client::ParentWindowWithContext(
         target, target_root, gfx::Rect(last_location_, gfx::Size()));
-    wm::ReparentTransientChildrenOfChild(target, old_parent, target->parent());
+    ash::wm::ReparentTransientChildrenOfChild(
+        ash::wm::WmWindowAura::Get(target),
+        ash::wm::WmWindowAura::Get(old_parent),
+        ash::wm::WmWindowAura::Get(target->parent()));
   }
 
   // If we started the drag in one root window and moved into another root