Disabling pyauto PDF 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 43 matching lines @@
       'infobars',
       'instant',
       # crbug.com/83459
       '-instant.InstantTest.testPreFetchInstantURLSetsNoCookies',
       'navigation',
       'notifications',
       'ntp',
       'omnibox',
       '-omnibox.OmniboxTest.testHistoryResult',  # crbug.com/71715
       'passwords',
-      'pdf',
+      '-pdf',  # crbug.com/83763
       'plugins',
       'plugins_check',
       'popups',
       # crbug.com/82629 - real bug.
       '-popups.PopupsTest.testPopupsLaunchUponBrowserBackButton',
       # crbug.com/47935
       '-popups.PopupsTest.testBlockedPopupNotShowInHistory',
       'prefs',
       'search_engines',
       'shortcuts',
@@ skipping 164 matching lines @@
   # HTML5 media performance tests.
   'MEDIA_TESTS': {
     'linux': [
       'media.media_playbacktime',
       'media.media_perf',
       'media.media_fps',
       'media.media_event_simple_test',
     ],
   },
 }