mus: Adds WindowManagerDelegate::OnWmConnected()

ui/aura/mus/window_manager_delegate.h

Index: ui/aura/mus/window_manager_delegate.h
diff --git a/ui/aura/mus/window_manager_delegate.h b/ui/aura/mus/window_manager_delegate.h
index 81189a159a6ca130cd91b4f78cd101a91dbdab5b..6e5b269f68e4d6c583216fe6c9a11e782f4f7d71 100644
--- a/ui/aura/mus/window_manager_delegate.h
+++ b/ui/aura/mus/window_manager_delegate.h
@@ -79,6 +79,9 @@ class AURA_EXPORT WindowManagerDelegate {
   // the WindowManager.
   virtual void SetWindowManagerClient(WindowManagerClient* client) = 0;
 
+  // Called when the connection to mus has been fully established.
+  virtual void OnWmConnected();
+
   // A client requested the bounds of |window| to change to |bounds|.
   virtual void OnWmSetBounds(Window* window, const gfx::Rect& bounds) = 0;