Moves Shell::CreateShelf() to WmShell

ash/root_window_controller.h

Index: ash/root_window_controller.h
diff --git a/ash/root_window_controller.h b/ash/root_window_controller.h
index ec746846852ba043c3e1032bc0587eff305085d8..2cd9a7c69fc2b9889f0bc058e5275d47a2f072f6 100644
--- a/ash/root_window_controller.h
+++ b/ash/root_window_controller.h
@@ -143,9 +143,6 @@ class ASH_EXPORT RootWindowController : public ShellObserver {
   aura::Window* GetContainer(int container_id);
   const aura::Window* GetContainer(int container_id) const;
 
-  // Creates the shelf for this root window and notifies observers.
-  void CreateShelf();
-
   // Called when the login status changes after login (such as lock/unlock).
   // TODO(oshima): Investigate if we can merge this and |OnLoginStateChanged|.
   void UpdateAfterLoginStatusChange(LoginStatus status);