Bug 1588284 - disable test_ext_web_accessible_incognito.html on fission r=mccr8

Differential Revision: https://phabricator.services.mozilla.com/D50161

--HG--
extra : moz-landing-system : lando

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

@@ -128,7 +128,7 @@ skip-if = os == 'android'
 [test_ext_web_accessible_resources.html]
 skip-if = os == 'android' && debug # bug 1397615
 [test_ext_web_accessible_incognito.html]
-skip-if = os == 'android' # bug 1397615 and bug 1513544
+skip-if = (os == 'android') || fission # Crashes intermittently: @ mozilla::dom::BrowsingContext::CreateFromIPC(mozilla::dom::BrowsingContext::IPCInitializer&&, mozilla::dom::BrowsingContextGroup*, mozilla::dom::ContentParent*), bug 1588284, bug 1397615 and bug 1513544
 [test_ext_webnavigation.html]
 skip-if = os == 'android' && debug # bug 1397615
 [test_ext_webnavigation_filters.html]