We need to monkey-patch setTimeout for Sandbox contexts.

release-browser/wrapper.prefix

@@ -27,3 +27,8 @@
     }
 })(function () {
     return function () {
+
+// Monkeypatch setTimeout so that the Closure Compiler
+// output can use it in a Sandbox context.
+var { setTimeout } = require("sdk/timers");
+this.setTimeout = setTimeout;