deleted file mode 100644
--- a/testing/firefox-ui/harness/firefox_ui_harness/decorators.py
+++ /dev/null
@@ -1,14 +0,0 @@
-# This Source Code Form is subject to the terms of the Mozilla Public
-# License, v. 2.0. If a copy of the MPL was not distributed with this file,
-# You can obtain one at http://mozilla.org/MPL/2.0/.
-
-from marionette import SkipTest
-import os
-
-
-def skip_under_xvfb(target):
-    def wrapper(self, *args, **kwargs):
-        if os.environ.get('MOZ_XVFB'):
-            raise SkipTest("Skipping due to running under xvfb")
-        return target(self, *args, **kwargs)
-    return wrapper

--- a/testing/firefox-ui/tests/firefox_ui_tests/functional/locationbar/test_access_locationbar.py
+++ b/testing/firefox-ui/tests/firefox_ui_tests/functional/locationbar/test_access_locationbar.py
@@ -1,15 +1,14 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 from marionette_driver import Wait
 
-from firefox_ui_harness.decorators import skip_under_xvfb
 from firefox_puppeteer.testcases import FirefoxTestCase
 
 
 class TestAccessLocationBar(FirefoxTestCase):
 
     def setUp(self):
         FirefoxTestCase.setUp(self)
 
@@ -23,17 +22,16 @@ class TestAccessLocationBar(FirefoxTestC
         ]
         self.test_urls = [self.marionette.absolute_url(t)
                           for t in self.test_urls]
 
         self.locationbar = self.browser.navbar.locationbar
         self.autocomplete_results = self.locationbar.autocomplete_results
         self.urlbar = self.locationbar.urlbar
 
-    @skip_under_xvfb
     def test_access_locationbar_history(self):
 
         # Open some local pages, then about:blank
         def load_urls():
             with self.marionette.using_context('content'):
                 for url in self.test_urls:
                     self.marionette.navigate(url)
         self.places.wait_for_visited(self.test_urls, load_urls)

--- a/testing/firefox-ui/tests/firefox_ui_tests/functional/locationbar/test_escape_autocomplete.py
+++ b/testing/firefox-ui/tests/firefox_ui_tests/functional/locationbar/test_escape_autocomplete.py
@@ -1,15 +1,14 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 from marionette_driver import Wait
 
-from firefox_ui_harness.decorators import skip_under_xvfb
 from firefox_puppeteer.testcases import FirefoxTestCase
 
 
 class TestEscapeAutocomplete(FirefoxTestCase):
 
     def setUp(self):
         FirefoxTestCase.setUp(self)
 
@@ -27,17 +26,16 @@ class TestEscapeAutocomplete(FirefoxTest
 
         self.locationbar = self.browser.navbar.locationbar
         self.autocomplete_results = self.locationbar.autocomplete_results
 
     def tearDown(self):
         self.autocomplete_results.close(force=True)
         FirefoxTestCase.tearDown(self)
 
-    @skip_under_xvfb
     def test_escape_autocomplete(self):
         # Open some local pages
         def load_urls():
             with self.marionette.using_context('content'):
                 for url in self.test_urls:
                     self.marionette.navigate(url)
         self.places.wait_for_visited(self.test_urls, load_urls)
 

--- a/testing/firefox-ui/tests/firefox_ui_tests/functional/locationbar/test_favicon_in_autocomplete.py
+++ b/testing/firefox-ui/tests/firefox_ui_tests/functional/locationbar/test_favicon_in_autocomplete.py
@@ -1,15 +1,14 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 from marionette_driver import Wait
 
-from firefox_ui_harness.decorators import skip_under_xvfb
 from firefox_puppeteer.testcases import FirefoxTestCase
 
 
 class TestFaviconInAutocomplete(FirefoxTestCase):
 
     PREF_SUGGEST_SEARCHES = 'browser.urlbar.suggest.searches'
     PREF_SUGGEST_BOOKMARK = 'browser.urlbar.suggest.bookmark'
 
@@ -30,17 +29,16 @@ class TestFaviconInAutocomplete(FirefoxT
         self.autocomplete_results = self.browser.navbar.locationbar.autocomplete_results
 
     def tearDown(self):
         try:
             self.autocomplete_results.close(force=True)
         finally:
             FirefoxTestCase.tearDown(self)
 
-    @skip_under_xvfb
     def test_favicon_in_autocomplete(self):
         # Open the test page
         def load_urls():
             with self.marionette.using_context('content'):
                 self.marionette.navigate(self.test_urls[0])
         self.places.wait_for_visited(self.test_urls, load_urls)
 
         locationbar = self.browser.navbar.locationbar

--- a/testing/firefox-ui/tests/firefox_ui_tests/functional/locationbar/test_suggest_bookmarks.py
+++ b/testing/firefox-ui/tests/firefox_ui_tests/functional/locationbar/test_suggest_bookmarks.py
@@ -1,15 +1,14 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 from marionette_driver import By, Wait
 
-from firefox_ui_harness.decorators import skip_under_xvfb
 from firefox_puppeteer.testcases import FirefoxTestCase
 
 
 class TestStarInAutocomplete(FirefoxTestCase):
     """ This replaces
     http://hg.mozilla.org/qa/mozmill-tests/file/default/firefox/tests/functional/testAwesomeBar/testSuggestBookmarks.js
     Check a star appears in autocomplete list for a bookmarked page.
     """
@@ -38,17 +37,16 @@ class TestStarInAutocomplete(FirefoxTest
                   arguments[0].hidePopup();
                 """, script_args=[self.bookmark_panel])
 
             self.browser.navbar.locationbar.autocomplete_results.close()
             self.places.restore_default_bookmarks()
         finally:
             FirefoxTestCase.tearDown(self)
 
-    @skip_under_xvfb
     def test_star_in_autocomplete(self):
         search_string = 'grants'
 
         def visit_urls():
             with self.marionette.using_context('content'):
                 for url in self.test_urls:
                     self.marionette.navigate(url)
 

--- a/testing/firefox-ui/tests/firefox_ui_tests/functional/security/test_dv_certificate.py
+++ b/testing/firefox-ui/tests/firefox_ui_tests/functional/security/test_dv_certificate.py
@@ -1,15 +1,14 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 from marionette_driver import Wait
 
-from firefox_ui_harness.decorators import skip_under_xvfb
 from firefox_puppeteer.testcases import FirefoxTestCase
 
 
 class TestDVCertificate(FirefoxTestCase):
 
     def setUp(self):
         FirefoxTestCase.setUp(self)
 
@@ -21,17 +20,16 @@ class TestDVCertificate(FirefoxTestCase)
     def tearDown(self):
         try:
             self.browser.switch_to()
             self.identity_popup.close(force=True)
             self.windows.close_all([self.browser])
         finally:
             FirefoxTestCase.tearDown(self)
 
-    @skip_under_xvfb
     def test_dv_cert(self):
         with self.marionette.using_context('content'):
             self.marionette.navigate(self.url)
 
         # The lock icon should be shown
         self.assertIn('identity-secure',
                       self.locationbar.connection_icon.value_of_css_property('list-style-image'))
 

--- a/testing/firefox-ui/tests/firefox_ui_tests/functional/security/test_ev_certificate.py
+++ b/testing/firefox-ui/tests/firefox_ui_tests/functional/security/test_ev_certificate.py
@@ -1,15 +1,14 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 from marionette_driver import Wait
 
-from firefox_ui_harness.decorators import skip_under_xvfb
 from firefox_puppeteer.testcases import FirefoxTestCase
 
 
 class TestEVCertificate(FirefoxTestCase):
 
     def setUp(self):
         FirefoxTestCase.setUp(self)
 
@@ -21,17 +20,16 @@ class TestEVCertificate(FirefoxTestCase)
     def tearDown(self):
         try:
             self.browser.switch_to()
             self.identity_popup.close(force=True)
             self.windows.close_all([self.browser])
         finally:
             FirefoxTestCase.tearDown(self)
 
-    @skip_under_xvfb
     def test_ev_certificate(self):
         with self.marionette.using_context('content'):
             self.marionette.navigate(self.url)
 
         # The lock icon should be shown
         self.assertIn('identity-secure',
                       self.locationbar.connection_icon.value_of_css_property('list-style-image'))
 

--- a/testing/firefox-ui/tests/firefox_ui_tests/functional/security/test_mixed_content_page.py
+++ b/testing/firefox-ui/tests/firefox_ui_tests/functional/security/test_mixed_content_page.py
@@ -1,15 +1,14 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 from marionette_driver import Wait
 
-from firefox_ui_harness.decorators import skip_under_xvfb
 from firefox_puppeteer.testcases import FirefoxTestCase
 
 
 class TestMixedContentPage(FirefoxTestCase):
     def setUp(self):
         FirefoxTestCase.setUp(self)
 
         self.locationbar = self.browser.navbar.locationbar
@@ -18,17 +17,16 @@ class TestMixedContentPage(FirefoxTestCa
         self.url = 'https://mozqa.com/data/firefox/security/mixedcontent.html'
 
     def tearDown(self):
         try:
             self.identity_popup.close(force=True)
         finally:
             FirefoxTestCase.tearDown(self)
 
-    @skip_under_xvfb
     def test_mixed_content(self):
         with self.marionette.using_context('content'):
             self.marionette.navigate(self.url)
 
         self.assertIn('identity-mixed-passive-loaded',
                       self.locationbar.connection_icon.value_of_css_property('list-style-image'))
 
         # Open the identity popup

--- a/testing/firefox-ui/tests/firefox_ui_tests/functional/security/test_mixed_script_content_blocking.py
+++ b/testing/firefox-ui/tests/firefox_ui_tests/functional/security/test_mixed_script_content_blocking.py
@@ -1,15 +1,14 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 from marionette_driver import By, Wait
 
-from firefox_ui_harness.decorators import skip_under_xvfb
 from firefox_puppeteer.testcases import FirefoxTestCase
 
 
 class TestMixedScriptContentBlocking(FirefoxTestCase):
 
     def setUp(self):
         FirefoxTestCase.setUp(self)
 
@@ -61,17 +60,16 @@ class TestMixedScriptContentBlocking(Fir
                 )
 
     def expect_protection_enabled(self):
         self._expect_protection_status(True)
 
     def expect_protection_disabled(self):
         self._expect_protection_status(False)
 
-    @skip_under_xvfb
     def test_mixed_content_page(self):
         with self.marionette.using_context('content'):
             self.marionette.navigate(self.url)
 
         self.expect_protection_enabled()
 
         # Disable mixed content blocking via identity popup
         self.locationbar.open_identity_popup()

--- a/testing/firefox-ui/tests/firefox_ui_tests/functional/security/test_no_certificate.py
+++ b/testing/firefox-ui/tests/firefox_ui_tests/functional/security/test_no_certificate.py
@@ -1,17 +1,16 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 from urlparse import urlparse
 
 from marionette_driver import expected, Wait
 
-from firefox_ui_harness.decorators import skip_under_xvfb
 from firefox_puppeteer.testcases import FirefoxTestCase
 
 
 class TestNoCertificate(FirefoxTestCase):
 
     def setUp(self):
         FirefoxTestCase.setUp(self)
 
@@ -23,17 +22,16 @@ class TestNoCertificate(FirefoxTestCase)
     def tearDown(self):
         try:
             self.browser.switch_to()
             self.identity_popup.close(force=True)
             self.windows.close_all([self.browser])
         finally:
             FirefoxTestCase.tearDown(self)
 
-    @skip_under_xvfb
     def test_no_certificate(self):
         with self.marionette.using_context('content'):
             self.marionette.navigate(self.url)
 
         # Check the favicon
         # TODO: find a better way to check, e.g., mozmill's isDisplayed
         favicon_hidden = self.marionette.execute_script("""
           return arguments[0].hasAttribute("hidden");

--- a/testing/firefox-ui/tests/firefox_ui_tests/functional/security/test_ssl_status_after_restart.py
+++ b/testing/firefox-ui/tests/firefox_ui_tests/functional/security/test_ssl_status_after_restart.py
@@ -1,16 +1,15 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 from marionette_driver import Wait
 from marionette.marionette_test import skip_if_e10s
 
-from firefox_ui_harness.decorators import skip_under_xvfb
 from firefox_puppeteer.testcases import FirefoxTestCase
 
 
 class TestSSLStatusAfterRestart(FirefoxTestCase):
 
     def setUp(self):
         FirefoxTestCase.setUp(self)
 
@@ -43,17 +42,16 @@ class TestSSLStatusAfterRestart(FirefoxT
             self.windows.close_all([self.browser])
             self.browser.tabbar.close_all_tabs([self.browser.tabbar.tabs[0]])
             self.browser.switch_to()
             self.identity_popup.close(force=True)
         finally:
             FirefoxTestCase.tearDown(self)
 
     @skip_if_e10s
-    @skip_under_xvfb
     def test_ssl_status_after_restart(self):
         for item in self.test_data:
             with self.marionette.using_context('content'):
                 self.marionette.navigate(item['url'])
             self.verify_certificate_status(item)
             self.browser.tabbar.open_tab()
 
         self.restart()

--- a/testing/firefox-ui/tests/firefox_ui_tests/puppeteer/test_toolbars.py
+++ b/testing/firefox-ui/tests/firefox_ui_tests/puppeteer/test_toolbars.py
@@ -1,16 +1,15 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 from marionette_driver import expected, By, Wait
 from marionette_driver.errors import NoSuchElementException
 
-from firefox_ui_harness.decorators import skip_under_xvfb
 from firefox_puppeteer.testcases import FirefoxTestCase
 
 
 class TestNavBar(FirefoxTestCase):
 
     def setUp(self):
         FirefoxTestCase.setUp(self)
 
@@ -147,46 +146,42 @@ class TestAutoCompleteResults(FirefoxTes
             self.autocomplete_results.close(force=True)
         except NoSuchElementException:
             # TODO: A NoSuchElementException is thrown here when tests accessing the
             # autocomplete_results element are skipped.
             pass
         finally:
             FirefoxTestCase.tearDown(self)
 
-    @skip_under_xvfb
     def test_popup_elements(self):
         # TODO: This test is not very robust because it relies on the history
         # in the default profile.
         self.assertFalse(self.autocomplete_results.is_open)
         self.browser.navbar.locationbar.urlbar.send_keys('a')
         results = self.autocomplete_results.results
         Wait(self.marionette).until(lambda _: self.autocomplete_results.is_complete)
         visible_result_count = len(self.autocomplete_results.visible_results)
         self.assertTrue(visible_result_count > 0)
         self.assertEqual(visible_result_count,
                          int(results.get_attribute('itemCount')))
 
-    @skip_under_xvfb
     def test_close(self):
         self.browser.navbar.locationbar.urlbar.send_keys('a')
         Wait(self.marionette).until(lambda _: self.autocomplete_results.is_open)
         # The Wait in the library implementation will fail this if this doesn't
         # end up closing.
         self.autocomplete_results.close()
 
-    @skip_under_xvfb
     def test_force_close(self):
         self.browser.navbar.locationbar.urlbar.send_keys('a')
         Wait(self.marionette).until(lambda _: self.autocomplete_results.is_open)
         # The Wait in the library implementation will fail this if this doesn't
         # end up closing.
         self.autocomplete_results.close(force=True)
 
-    @skip_under_xvfb
     def test_matching_text(self):
         # The default profile always has links to mozilla.org. So multiple results
         # will be found with 'moz'.
         input_text = 'moz'
 
         self.browser.navbar.locationbar.urlbar.send_keys(input_text)
         Wait(self.marionette).until(lambda _: self.autocomplete_results.is_complete)
         visible_results = self.autocomplete_results.visible_results
@@ -217,17 +212,16 @@ class TestIdentityPopup(FirefoxTestCase)
             self.marionette.navigate(self.url)
 
     def tearDown(self):
         try:
             self.identity_popup.close(force=True)
         finally:
             FirefoxTestCase.tearDown(self)
 
-    @skip_under_xvfb
     def test_elements(self):
         self.locationbar.open_identity_popup()
 
         self.assertEqual(self.identity_popup.host.get_attribute('localName'), 'broadcaster')
 
         # Test main view elements
         main = self.identity_popup.view.main
         self.assertEqual(main.element.get_attribute('localName'), 'panelview')
@@ -257,29 +251,27 @@ class TestIdentityPopup(FirefoxTestCase)
 
         self.assertEqual(security.disable_mixed_content_blocking_button.get_attribute('localName'),
                          'button')
         self.assertEqual(security.enable_mixed_content_blocking_button.get_attribute('localName'),
                          'button')
 
         self.assertEqual(security.more_info_button.get_attribute('localName'), 'button')
 
-    @skip_under_xvfb
     def test_open_close(self):
         with self.marionette.using_context('content'):
             self.marionette.navigate(self.url)
 
         self.assertFalse(self.identity_popup.is_open)
 
         self.locationbar.open_identity_popup()
 
         self.identity_popup.close()
         self.assertFalse(self.identity_popup.is_open)
 
-    @skip_under_xvfb
     def test_force_close(self):
         with self.marionette.using_context('content'):
             self.marionette.navigate(self.url)
 
         self.assertFalse(self.identity_popup.is_open)
 
         self.locationbar.open_identity_popup()