Check WindowTreeClient for empty inflight queue upon teardown

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

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/mus/public/cpp/tests/window_tree_client_private.h"
 
+#include "base/run_loop.h"
+#include "components/mus/public/cpp/lib/in_flight_change.h"
 #include "components/mus/public/cpp/window.h"
 #include "components/mus/public/cpp/window_tree_client.h"
 
 namespace mus {
 
 WindowTreeClientPrivate::WindowTreeClientPrivate(
     WindowTreeClient* tree_client_impl)
     : tree_client_impl_(tree_client_impl) {}
 
 WindowTreeClientPrivate::WindowTreeClientPrivate(Window* window)
@@ skipping 19 matching lines @@
 
 void WindowTreeClientPrivate::CallOnWindowInputEvent(
     Window* window,
     std::unique_ptr<ui::Event> event) {
   const uint32_t event_id = 0u;
   const uint32_t observer_id = 0u;
   tree_client_impl_->OnWindowInputEvent(event_id, window->server_id(),
                                         std::move(event), observer_id);
 }
 
+void WindowTreeClientPrivate::ClearInFlightQueue() {
+  tree_client_impl_->in_flight_map_.clear();
+}
+
+void WindowTreeClientPrivate::WaitForInFlightQueue() {
+  while (!tree_client_impl_->in_flight_map_.empty()) {
+    base::RunLoop run_loop;
+    run_loop.RunUntilIdle();
+  }
+}
+
 }  // namespace mus