Add desktopui_IBusTest, that checks if IBus is working properly.

client/deps/ibusclient/src/ibusclient.cc

Index: client/deps/ibusclient/src/ibusclient.cc
diff --git a/client/deps/ibusclient/src/ibusclient.cc b/client/deps/ibusclient/src/ibusclient.cc
new file mode 100644
index 0000000000000000000000000000000000000000..4f053a1c969970ddc78207a4430df1eb62f0a2e0
--- /dev/null
+++ b/client/deps/ibusclient/src/ibusclient.cc
@@ -0,0 +1,16 @@
+// Copyright (c) 2010 The Chromium OS 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 <assert.h>
+#include <ibus.h>
+
+int main(int argc, char **argv) {
+  ibus_init();
+  IBusBus* ibus = ibus_bus_new();
+  assert(ibus);
+  // This fails if ibus daemon is not running.
+  assert(ibus_bus_is_connected(ibus));
+  // TODO(satorux): Add more tests.
+  return 0;
+}