Bug 1580848 - Add ContentTaskUtils to SpecialPowers.spawn execution scope. r=kmag

Differential Revision: https://phabricator.services.mozilla.com/D45745

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

testing/specialpowers/content/SpecialPowersChild.jsm

@@ -55,12 +55,16 @@ ChromeUtils.defineModuleGetter(
   "AppConstants",
   "resource://gre/modules/AppConstants.jsm"
 );
-
 ChromeUtils.defineModuleGetter(
   this,
   "PerTestCoverageUtils",
   "resource://testing-common/PerTestCoverageUtils.jsm"
 );
+ChromeUtils.defineModuleGetter(
+  this,
+  "ContentTaskUtils",
+  "resource://testing-common/ContentTaskUtils.jsm"
+);
 
 // Allow stuff from this scope to be accessed from non-privileged scopes. This
 // would crash if used outside of automation.
@@ -1676,6 +1680,7 @@ class SpecialPowersChild extends JSWindowActorChild {
     });
 
     sb.sandbox.SpecialPowers = this;
+    sb.sandbox.ContentTaskUtils = ContentTaskUtils;
     Object.defineProperty(sb.sandbox, "content", {
       get: () => {
         return this.contentWindow;