Enable policy_prefs_ui.py and disable only the broken policy.

chrome/test/functional/PYAUTO_TESTS

 # Copyright (c) 2011 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 file lists the pyauto tests that run as a part of the functional test
 # suite.
 #
 # Tests can be enabled on a per-platform basis. Tests not listed here will
 # not be run.
 #
@@ skipping 147 matching lines @@
       '-sync',
       # crbug.com/86949
       '-sync.SyncTest.testRestartBrowser',
       # crbug.com/87642
       '-sync.SyncTest.testDisableAndEnableDatatypes',
       # crbug.com/95621
       '-youtube.YoutubeTest.testPlayerStatus',
       # crbug.com/98526
       '-pyauto_webdriver.PyAutoWebDriverTest.testCanConnectToRestartedBrowser',
       '-pyauto_webdriver.PyAutoWebDriverTest.testTypeIntoTextBox',
-      # crbug.com/102136
-      '-policy_prefs_ui.PolicyPrefsUITest.testPoliciesShowBanner',
     ],
 
     'mac': [
       # ==================================================
       # Disabled tests that need to be investigated/fixed.
       # ==================================================
       # Keychain popups make autofill/password tests difficult: crbug.com/49378
       '-autofill',
       # Autofill on Mac. crbug.com/95165
       '-browsing_data.BrowsingDataTest.testClearAutofillData',
@@ skipping 402 matching lines @@
 
   # HTML5 media functional tests.
   'AV_FUNC': {
      'linux': [
        'media.media_event_simple_action',
        'media.media_event_simple_test',
        'media.media_event_track',
      ],
   },
 }