[chromedriver] Add Network Conditions Override Manager and tests

chrome/test/chromedriver/chrome/network_conditions.h

Index: chrome/test/chromedriver/chrome/network_conditions.h
diff --git a/chrome/test/chromedriver/chrome/network_conditions.h b/chrome/test/chromedriver/chrome/network_conditions.h
new file mode 100644
index 0000000000000000000000000000000000000000..223365508b1c8a8b0b8b4a39b993503e6a7d5bc8
--- /dev/null
+++ b/chrome/test/chromedriver/chrome/network_conditions.h
@@ -0,0 +1,15 @@
+// Copyright (c) 2015 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.
+
+#ifndef CHROME_TEST_CHROMEDRIVER_CHROME_NETWORK_CONDITIONS_H_
+#define CHROME_TEST_CHROMEDRIVER_CHROME_NETWORK_CONDITIONS_H_
+
+struct NetworkConditions {
+  bool offline;
+  double latency;
+  double download_throughput;
+  double upload_throughput;
+};
+
+#endif  // CHROME_TEST_CHROMEDRIVER_CHROME_NETWORK_CONDITIONS_H_