Bug 1434744 - disable test_allowMedia.html on mac shippable, win debug and linux18.04 qr debug r=egao

Differential Revision: https://phabricator.services.mozilla.com/D72728

dom/html/test/mochitest.ini

@@ -589,7 +589,7 @@ skip-if = (os == 'android' || os == 'mac')
 skip-if = (os == 'mac')
 [test_bug1260704.html]
 [test_allowMedia.html]
-skip-if = (verify && (os == 'linux' || os == 'win'))
+skip-if = (verify && (os == 'linux' || os == 'win')) || ((!debug && os == "mac" && bits == 64) || (debug && os == "win") || (debug && webrender && os == "linux" && os_version == '18.04')) #Bug 1434744
 [test_bug1292522_same_domain_with_different_port_number.html]
 [test_bug1295719_event_sequence_for_arrow_keys.html]
 skip-if = os == "android" # up/down arrow keys not supported on android