Wires up transient windows for aura-mus

ui/aura/test/mus/test_window_tree.cc

Index: ui/aura/test/mus/test_window_tree.cc
diff --git a/ui/aura/test/mus/test_window_tree.cc b/ui/aura/test/mus/test_window_tree.cc
index 9e300587f96a0d1a6f454e897237acfa255028f7..c83f2f0ad5f3e97f7d884aad5dc8afac68136514 100644
--- a/ui/aura/test/mus/test_window_tree.cc
+++ b/ui/aura/test/mus/test_window_tree.cc
@@ -181,13 +181,17 @@ void TestWindowTree::RemoveWindowFromParent(uint32_t change_id,
 void TestWindowTree::AddTransientWindow(uint32_t change_id,
                                         uint32_t window_id,
                                         uint32_t transient_window_id) {
-  OnChangeReceived(change_id);
+  transient_data_.parent_id = window_id;
+  transient_data_.child_id = transient_window_id;
+  OnChangeReceived(change_id, WindowTreeChangeType::ADD_TRANSIENT);
 }
 
 void TestWindowTree::RemoveTransientWindowFromParent(
     uint32_t change_id,
     uint32_t transient_window_id) {
-  OnChangeReceived(change_id);
+  transient_data_.parent_id = kInvalidServerId;
+  transient_data_.child_id = transient_window_id;
+  OnChangeReceived(change_id, WindowTreeChangeType::REMOVE_TRANSIENT);
 }
 
 void TestWindowTree::SetModal(uint32_t change_id, uint32_t window_id) {