[Telemetry] Explictly intialize & clean up network_controller

telemetry/telemetry/testing/serially_executed_browser_test_case.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 unittest
 
 from catapult_base import cloud_storage
 from telemetry.internal.browser import browser_finder
 from telemetry.testing import options_for_unittests
 from telemetry.util import wpr_modes
@@ skipping 28 matching lines @@
   def SetBrowserOptions(cls, browser_options):
     """Sets the browser option for the browser to create.
 
     Args:
       browser_options: Browser options object for the browser we want to test.
     """
     cls._browser_options = browser_options
     cls._browser_to_create = browser_finder.FindBrowser(browser_options)
     if not cls.platform:
       cls.platform = cls._browser_to_create.platform
+      cls.platform.network_controller.InitializeIfNeeded()
     else:
       assert cls.platform == cls._browser_to_create.platform, (
           'All browser launches within same test suite must use browsers on '
           'the same platform')
 
   @classmethod
   def StartWPRServer(cls, archive_path=None, archive_bucket=None):
     """Start a webpage replay server.
 
     Args:
@@ skipping 26 matching lines @@
   @classmethod
   def StopBrowser(cls):
     assert cls.browser, 'Browser is not started'
     cls.browser.Close()
     cls.browser = None
 
   @classmethod
   def tearDownClass(cls):
     if cls.platform:
       cls.platform.StopAllLocalServers()
+      cls.platform.network_controller.Close()
     if cls.browser:
       cls.StopBrowser()
 
   @classmethod
   def SetStaticServerDir(cls, dir_path):
     assert cls.platform
     cls.platform.SetHTTPServerDirectories(dir_path)
 
   @classmethod
   def UrlOfStaticFilePath(cls, file_path):
     return cls.platform.http_server.UrlOf(file_path)