Bug 1444758: Follow-up: Disable test_ext_unload_frame for too frequent intermittent failures. r=bustage DONTBUILD

MozReview-Commit-ID: 7HrXu2mcnmW

toolkit/components/extensions/test/xpcshell/xpcshell-common.ini

@@ -103,6 +103,7 @@ skip-if = os == 'android' # Bug 1258975 on android.
 [test_ext_topSites.js]
 skip-if = os == "android"
 [test_ext_unload_frame.js]
+skip-if = true # Too frequent intermittent failures
 [test_ext_webRequest_filterResponseData.js]
 [test_ext_webRequest_permission.js]
 [test_ext_webRequest_responseBody.js]