Add xidle library to power_manager for testing how long the user has been idle

src/platform/power_manager/testrunner.cc

Index: src/platform/power_manager/testrunner.cc
diff --git a/src/platform/power_manager/testrunner.cc b/src/platform/power_manager/testrunner.cc
new file mode 100644
index 0000000000000000000000000000000000000000..7aa22c3477f72e399e8c8ee1302eeb6610aa6dec
--- /dev/null
+++ b/src/platform/power_manager/testrunner.cc
@@ -0,0 +1,10 @@
+// Copyright (c) 2009 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 <gtest/gtest.h>
+
+int main(int argc, char **argv) {
+  ::testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}