Removes a couple more functions from WmWindow

ash/wm/panels/panel_layout_manager.cc

Index: ash/wm/panels/panel_layout_manager.cc
diff --git a/ash/wm/panels/panel_layout_manager.cc b/ash/wm/panels/panel_layout_manager.cc
index c3d9cd133a5d4cbc978115c215452e82e02d08eb..64785205a5e28c1b4197df8346a359c2eb04dc46 100644
--- a/ash/wm/panels/panel_layout_manager.cc
+++ b/ash/wm/panels/panel_layout_manager.cc
@@ -222,7 +222,7 @@ class PanelCalloutWidget : public views::Widget {
     params.bounds.set_height(kArrowHeight);
     params.accept_events = false;
     parent->GetRootWindowController()->ConfigureWidgetInitParamsForContainer(
-        this, parent->GetShellWindowId(), &params);
+        this, parent->aura_window()->id(), &params);
     set_focus_on_creation(false);
     Init(params);
     WmWindow* widget_window = WmWindow::Get(this->GetNativeWindow());
@@ -274,8 +274,8 @@ PanelLayoutManager* PanelLayoutManager::Get(WmWindow* window) {
 
   return static_cast<PanelLayoutManager*>(
       window->GetRootWindow()
-          ->GetChildByShellWindowId(kShellWindowId_PanelContainer)
           ->aura_window()
+          ->GetChildById(kShellWindowId_PanelContainer)
           ->layout_manager());
 }