Bug 1174977 - Skip the privatebrowsing tests on Win8 due to being nearly permafail. a=me

browser/components/privatebrowsing/test/browser/browser.ini

@@ -1,5 +1,5 @@
 [DEFAULT]
-skip-if = buildapp == "mulet"
+skip-if = buildapp == "mulet" || (os == "win" && os_version == "6.2") # Win: bug 1173801, bug 1174977
 support-files =
   browser_privatebrowsing_concurrent_page.html
   browser_privatebrowsing_cookieacceptdialog.html
@@ -16,7 +16,6 @@ support-files =
   title.sjs
 
 [browser_privatebrowsing_DownloadLastDirWithCPS.js]
-skip-if = (os == "win" && os_version == "6.2") # bug 1173801
 [browser_privatebrowsing_aboutHomeButtonAfterWindowClose.js]
 [browser_privatebrowsing_aboutSessionRestore.js]
 [browser_privatebrowsing_cache.js]