[chromedriver] Add page loading strategy to capabilities

chrome/test/chromedriver/chrome/navigation_tracker_none.cc

+// Copyright (c) 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 "chrome/test/chromedriver/chrome/navigation_tracker_none.h"
+
+NavigationTrackerNone::~NavigationTrackerNone() {}
+
+Status NavigationTrackerNone::IsPendingNavigation(const std::string& frame_id,
+                                                  const Timeout* timeout,
+                                                  bool* is_pending) {
+  *is_pending = false;
+  return Status(kOk);
+}
+
+void NavigationTrackerNone::set_timed_out(bool timed_out) {
+  timed_out_ = timed_out;
+}