All SSL UI tests work with ephemeral ports.

net/tools/testserver/testserver.py

 #!/usr/bin/python2.4
 # Copyright (c) 2006-2010 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.
 
 """This is a simple HTTP server used for testing Chrome.
 
 It supports several test URLs, as specified by the handlers in TestPageHandler.
 It defaults to living on localhost:8888.
 It can use https if you specify the flag --https=CERT where CERT is the path
@@ skipping 558 matching lines @@
     self.server.waitForDownload = False
     self.send_response(200)
     self.send_header('Content-type', 'text/html')
     self.send_header('Cache-Control', 'max-age=0')
     self.end_headers()
     return True
 
   def _ReplaceFileData(self, data, query_parameters):
     """Replaces matching substrings in a file.
 
-    If the 'replace_orig' and 'replace_new' URL query parameters are present,
-    a new string is returned with all occasions of the 'replace_orig' value
-    replaced by the 'replace_new' value.
+    If the 'replace_text' URL query parameter is present, it is expected to be
+    of the form old_text:new_text, which indicates that any old_text strings in
+    the file are replaced with new_text. Multiple 'replace_text' parameters may
+    be specified.
 
     If the parameters are not present, |data| is returned.
     """
     query_dict = cgi.parse_qs(query_parameters)
-    orig_values = query_dict.get('replace_orig', [])
-    new_values = query_dict.get('replace_new', [])
-    if not orig_values or not new_values:
-      return data
-    orig_value = orig_values[0]
-    new_value = new_values[0]
-    return data.replace(orig_value, new_value)
+    replace_text_values = query_dict.get('replace_text', [])
+    for replace_text_value in replace_text_values:
+      replace_text_args = replace_text_value.split(':')
+      if len(replace_text_args) != 2:
+        raise ValueError(
+          'replace_text must be of form old_text:new_text. Actual value: %s' %
+          replace_text_value)
+      old_text_b64, new_text_b64 = replace_text_args
+      old_text = base64.urlsafe_b64decode(old_text_b64)
+      new_text = base64.urlsafe_b64decode(new_text_b64)
+      data = data.replace(old_text, new_text)
+    return data
 
   def FileHandler(self):
     """This handler sends the contents of the requested file.  Wow, it's like
     a real webserver!"""
 
     prefix = self.server.file_root_url
     if not self.path.startswith(prefix):
       return False
 
     # Consume a request body if present.
@@ skipping 671 matching lines @@
                            'option may appear multiple times, indicating '
                            'multiple algorithms should be enabled.');
   option_parser.add_option('', '--file-root-url', default='/files/',
                            help='Specify a root URL for files served.')
   option_parser.add_option('', '--startup-pipe', type='int',
                            dest='startup_pipe',
                            help='File handle of pipe to parent process')
   options, args = option_parser.parse_args()
 
   sys.exit(main(options, args))