Backed out changeset e12dcb4be855 (bug 1358914) for timing out in toolkit/components/extensions/test/mochitest/test_chrome_ext_hybrid_addons.html. r=backout

toolkit/mozapps/extensions/internal/XPIProvider.jsm

@@ -5217,7 +5217,15 @@ this.XPIProvider = {
         activeAddon.bootstrapScope, "console",
         () => new ConsoleAPI({ consoleID: "addon/" + aId }));
 
-      Services.scriptloader.loadSubScript(uri, activeAddon.bootstrapScope);
+      // As we don't want our caller to control the JS version used for the
+      // bootstrap file, we run loadSubScript within the context of the
+      // sandbox with the latest JS version set explicitly.
+      activeAddon.bootstrapScope.__SCRIPT_URI_SPEC__ = uri;
+      Components.utils.evalInSandbox(
+        "Components.classes['@mozilla.org/moz/jssubscript-loader;1'] \
+                   .getService(Components.interfaces.mozIJSSubScriptLoader) \
+                   .loadSubScript(__SCRIPT_URI_SPEC__);",
+                   activeAddon.bootstrapScope, "ECMAv5");
     } catch (e) {
       logger.warn("Error loading bootstrap.js for " + aId, e);
     }
@@ -5309,8 +5317,8 @@ this.XPIProvider = {
 
       let method = undefined;
       try {
-        let scope = activeAddon.bootstrapScope;
-        method = scope[aMethod] || Cu.evalInSandbox(`${aMethod};`, scope);
+        method = Components.utils.evalInSandbox(`${aMethod};`,
+          activeAddon.bootstrapScope, "ECMAv5");
       } catch (e) {
         // An exception will be caught if the expected method is not defined.
         // That will be logged below.