Add Video.testVideoSeeking test.

tools/chrome_proxy/webdriver/common.py

 # Copyright 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.
 
 import argparse
 import json
 import logging
 import os
 import re
 import socket
@@ skipping 572 matching lines @@
   def __str__(self):
     self_dict = {
       'response_headers': self._response_headers,
       'request_headers': self._request_headers,
       'url': self._url,
       'protocol': self._protocol,
       'port': self._port,
       'status': self._status,
       'request_type': self._request_type
     }
-    return json.dumps(self_dict)
+    return json.dumps(self_dict, indent=2)
 
   @property
   def response_headers(self):
     return self._response_headers
 
   @property
   def request_headers(self):
     return self._request_headers
 
   @property
@@ skipping 151 matching lines @@
     for test_suite in test_suite_iter:
       for test_case in test_suite:
         for test in test_case:
           # Drop the file name in the form <filename>.<classname>.<methodname>
           test_id = test.id()[test.id().find('.') + 1:]
           if re.match(test_filter_re, test_id):
             tests.addTest(test)
     testRunner = unittest.runner.TextTestRunner(verbosity=2,
       failfast=flags.failfast, buffer=(not flags.disable_buffer))
     testRunner.run(tests)