Wires up shelf to panel and dock layoutmanagers

mash/wm/bridge/wm_root_window_controller_mus.cc

Index: mash/wm/bridge/wm_root_window_controller_mus.cc
diff --git a/mash/wm/bridge/wm_root_window_controller_mus.cc b/mash/wm/bridge/wm_root_window_controller_mus.cc
index 658983700221f0fd708d64790bfbb3cfb5ba8f9f..9b01ef22aaaa1321fd29a21a1eeae9d6c3078555 100644
--- a/mash/wm/bridge/wm_root_window_controller_mus.cc
+++ b/mash/wm/bridge/wm_root_window_controller_mus.cc
@@ -106,8 +106,9 @@ void WmRootWindowControllerMus::ConfigureWidgetInitParamsForContainer(
     views::Widget* widget,
     int shell_container_id,
     views::Widget::InitParams* init_params) {
-  init_params->parent_mus =
-      root_window_controller_->root()->GetChildByLocalId(shell_container_id);
+  init_params->parent_mus = WmWindowMus::GetMusWindow(
+      WmWindowMus::Get(root_window_controller_->root())
+          ->GetChildByShellWindowId(shell_container_id));
   DCHECK(init_params->parent_mus);
   mus::Window* new_window =
       root_window_controller_->root()->connection()->NewWindow();