mus: Adds WindowManagerDelegate::OnWmConnected()

ash/mus/window_manager.cc

Index: ash/mus/window_manager.cc
diff --git a/ash/mus/window_manager.cc b/ash/mus/window_manager.cc
index 003dc5d0585b1958cb0c44923f70ff5c528a1093..a5b19687d6c4c2ac015d1156ba2e25aaa4fd43b5 100644
--- a/ash/mus/window_manager.cc
+++ b/ash/mus/window_manager.cc
@@ -330,6 +330,8 @@ void WindowManager::SetWindowManagerClient(aura::WindowManagerClient* client) {
   ash::Shell::set_window_manager_client(client);
 }
 
+void WindowManager::OnWmConnected() {}
+
 void WindowManager::OnWmSetBounds(aura::Window* window,
                                   const gfx::Rect& bounds) {
   // TODO(sky): this indirectly sets bounds, which is against what