bug 840592 - two tests XPCWrappedJS on wrong thread via JS nsISystemProxySettings implementations r=jduell

netwerk/test/unit/test_bug586908.js

@@ -27,6 +27,7 @@ var systemSettings = {
     throw Components.results.NS_ERROR_NOT_IMPLEMENTED;
   },
   
+  mainThreadOnly: true,
   PACURI: "http://localhost:4444/redirect",
   getProxyForURI: function(aURI) {
     throw Components.results.NS_ERROR_NOT_IMPLEMENTED;

services/common/tests/unit/head_helpers.js

@@ -138,6 +138,7 @@ let PACSystemSettings = {
 
   // Replace this URI for each test to avoid caching. We want to ensure that
   // each test gets a completely fresh setup.
+  mainThreadOnly: true,
   PACURI: null,
   getProxyForURI: function getProxyForURI(aURI) {
     throw Cr.NS_ERROR_NOT_IMPLEMENTED;