mus: Implement Window Server Capture

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 af526cdc7afb7a0e9a547ec744e497dafd4f1d2d..398a6613479d37e8e70069f8ba99dbbcabe68622 100644
--- a/components/mus/public/cpp/tests/test_window_tree.cc
+++ b/components/mus/public/cpp/tests/test_window_tree.cc
@@ -99,6 +99,16 @@ void TestWindowTree::ReorderWindow(uint32_t change_id,
 void TestWindowTree::GetWindowTree(uint32_t window_id,
                                    const GetWindowTreeCallback& callback) {}
 
+void TestWindowTree::SetCapture(uint32_t change_id, uint32_t window_id) {
+  got_change_ = true;
+  change_id_ = change_id;
+}
+
+void TestWindowTree::ReleaseCapture(uint32_t change_id, uint32_t window_id) {
+  got_change_ = true;
+  change_id_ = change_id;
+}
+
 void TestWindowTree::Embed(uint32_t window_id,
                            mojom::WindowTreeClientPtr client,
                            uint32_t policy_bitmask,