Bug 1566186: Part 1.1 - Disable failing mozbrowser test. r=me,test-only

--HG--
extra : rebase_source : f0c45cd5ea5516a220123ca1845aad73797c2b2e

dom/browser-element/mochitest/mochitest.ini

@@ -95,6 +95,7 @@ support-files =
 [test_browserElement_inproc_ThemeColor.html]
 [test_browserElement_inproc_AlertInFrame.html]
 [test_browserElement_inproc_Auth.html]
+disabled = No longer supported
 [test_browserElement_inproc_BrowserWindowNamespace.html]
 [test_browserElement_inproc_BrowserWindowResize.html]
 [test_browserElement_inproc_Close.html]