[telemetry] Add a webdriver backend with support for IE.

tools/telemetry/telemetry/core/wpr_server.py

 # Copyright (c) 2012 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 os
 import sys
 
 from telemetry.core import util
 
 # Get chrome/test/functional scripts into our path.
 # TODO(tonyg): Move webpagereplay.py to a common location.
@@ skipping 35 matching lines @@
       else:
         options.append('--record')
     if not make_javascript_deterministic:
       options.append('--inject_scripts=')
     self._web_page_replay = webpagereplay.ReplayServer(
         path,
         self._webpagereplay_host,
         self._webpagereplay_local_http_port,
         self._webpagereplay_local_https_port,
         options)
+    if browser_backend.browser_type.startswith('webdriver.'):

[tonyg, 2013/07/26 18:21:07]

I don't think it is good for the wpr_server to explicitly know about browsers.
Can we pass a use_dns_forwarding var to __init__ instead?

[chrisgao (Use stgao instead), 2013/07/30 02:06:49]

Done as discussed offline.

+      self._web_page_replay.replay_options.remove('--no-dns_forwarding')
     self._web_page_replay.StartServer()
 
   def __enter__(self):
     return self
 
   def __exit__(self, *args):
     self.Close()
 
   def Close(self):
     if self._forwarder:
       self._forwarder.Close()
       self._forwarder = None
     if self._web_page_replay:
       self._web_page_replay.StopServer()
       self._web_page_replay = None