Remove the navigation pyauto test. It duplicates existing chrome tests.

chrome/test/functional/PYAUTO_TESTS

 # 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.
 #
 # 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 31 matching lines @@
       'downloads',
       'execute_javascript',
       'extensions',
       'fullscreen_mouselock',
       'history',
       'gtalk.test_basic',
       'imports',
       'infobars',
       'instant',
       'multiprofile',
-      'navigation',
       'notifications',
       'ntp',
       'omnibox',
       'passwords',
       'policy',
       'policy_prefs_ui',
       'popups',
       'prefs',
       'prefs_ui',
       'pyauto_webdriver',
@@ skipping 743 matching lines @@
       '-search_engines.SearchEnginesTest.testDiscoverSearchEngine',
       '-ntp.NTPTest.testUninstallApp',
       '-ntp.NTPTest.testLaunchAppWithDefaultSettings',
       '-ntp.NTPTest.testLaunchAppRegularTab',
       '-ntp.NTPTest.testLaunchAppPinnedTab',
       '-ntp.NTPTest.testGetAppsWhenInstallApp',
       '-ntp.NTPTest.testLaunchAppNewWindow',
     ],
   },
 }