Bug 1461145: Follow-up follow-up: Fix setTimeout flakiness in tests that load SpecialPowersObserverAPI. r=bustage

MozReview-Commit-ID: 1JTl2Aj1wFK

testing/specialpowers/content/SpecialPowersObserverAPI.js

@@ -11,7 +11,6 @@ XPCOMUtils.defineLazyModuleGetters(this, {
   ExtensionTestCommon: "resource://testing-common/ExtensionTestCommon.jsm",
   NetUtil: "resource://gre/modules/NetUtil.jsm",
   Services: "resource://gre/modules/Services.jsm",
-  setTimeout: "resource://gre/modules/Timer.jsm",
 });
 
 this.SpecialPowersError = function(aMsg) {
@@ -641,6 +640,7 @@ SpecialPowersObserverAPI.prototype = {
         let id = aMessage.data.id;
         let extension = this._extensions.get(id);
         this._extensions.delete(id);
+        let {setTimeout} = ChromeUtils.import("resource://gre/modules/Timer.jsm", null);
         let done = () => {
           setTimeout(() => {
             this._sendReply(aMessage, "SPExtensionMessage", {id, type: "extensionUnloaded", args: []});