mus: Let clients set the cursor of their window.

components/mus/public/cpp/tests/test_window_tree.cc

Index: components/mus/public/cpp/tests/test_window_tree.cc
diff --git a/components/mus/public/cpp/tests/test_window_tree.cc b/components/mus/public/cpp/tests/test_window_tree.cc
index 46c6451143271e8ab182015cca9ba966706dda84..ba9d80059f016c544826b1865689d1e455eaa551 100644
--- a/components/mus/public/cpp/tests/test_window_tree.cc
+++ b/components/mus/public/cpp/tests/test_window_tree.cc
@@ -89,6 +89,10 @@ void TestWindowTree::SetFocus(uint32_t window_id) {}
 
 void TestWindowTree::SetCanFocus(uint32_t window_id, bool can_focus) {}
 
+void TestWindowTree::SetPredefinedCursor(uint32_t change_id,
+                                         uint32_t window_id,
+                                         mus::mojom::Cursor cursor_id) {}
+
 void TestWindowTree::SetWindowTextInputState(uint32_t window_id,
                                              mojo::TextInputStatePtr state) {}