Temporarily disable prefs pyauto tests broken by r70809

BUG=70809

TEST=
TBR=battre@chromium.org

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@72579 0039d316-1c4b-4281-b951-d872f2087c98

chrome/test/functional/PYAUTO_TESTS

@@ -67,6 +67,9 @@
       'popups',
       '-popups',  # Flaky. crbug.com/70659
       'prefs',
+      # Some pref tests broken by r72489. crbug.com/70809
+      '-prefs.PrefsTest.testUnderTheHoodPref',
+      '-prefs.PrefsTest.testHomepagePrefs',
       'search_engines',
       # crbug.com/67628
       '-search_engines.SearchEnginesTest.testTabToSearch',