[ChromeDriver] Support mobile emulation on desktop Chrome.

chrome/test/chromedriver/mobile_device.h

Index: chrome/test/chromedriver/mobile_device.h
diff --git a/chrome/test/chromedriver/mobile_device.h b/chrome/test/chromedriver/mobile_device.h
new file mode 100644
index 0000000000000000000000000000000000000000..5435407d33e2b43186161cf8c32c9f1a6eb081e5
--- /dev/null
+++ b/chrome/test/chromedriver/mobile_device.h
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+// Copyright (c) 2014 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_MOBILE_DEVICE_H_
+#define CHROME_TEST_CHROMEDRIVER_MOBILE_DEVICE_H_
+
+#include <string>
+#include "chrome/test/chromedriver/chrome/device_metrics.h"
+
+struct MobileDevice {
+  MobileDevice();
+  MobileDevice(DeviceMetrics device_metrics, std::string user_agent);
+  ~MobileDevice();
+  DeviceMetrics device_metrics;
+  std::string user_agent;
+};
+
+#endif  // CHROME_TEST_CHROMEDRIVER_MOBILE_DEVICE_H_