--- a/devtools/client/debugger/test/mochitest/code_frame-script.js
+++ b/devtools/client/debugger/test/mochitest/code_frame-script.js
@@ -1,16 +1,25 @@
 "use strict";
 
 var { classes: Cc, interfaces: Ci, utils: Cu } = Components;
 const { loadSubScript } = Cc['@mozilla.org/moz/jssubscript-loader;1'].
                           getService(Ci.mozIJSSubScriptLoader);
 
-const EventUtils = {};
-loadSubScript("chrome://marionette/content/EventUtils.js", EventUtils);
+// Set up a dummy environment so that EventUtils works. We need to be careful to
+// pass a window object into each EventUtils method we call rather than having
+// it rely on the |window| global.
+let EventUtils = {};
+EventUtils.window = content;
+EventUtils.parent = EventUtils.window;
+EventUtils._EU_Ci = Components.interfaces;
+EventUtils._EU_Cc = Components.classes;
+EventUtils.navigator = content.navigator;
+EventUtils.KeyboardEvent = content.KeyboardEvent;
+loadSubScript("chrome://mochikit/content/tests/SimpleTest/EventUtils.js", EventUtils);
 
 dump("Frame script loaded.\n");
 
 var workers = {}
 
 this.call = function (name, args) {
   dump("Calling function with name " + name + ".\n");
 

--- a/devtools/client/shared/frame-script-utils.js
+++ b/devtools/client/shared/frame-script-utils.js
@@ -1,21 +1,18 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 "use strict";
-var {classes: Cc, interfaces: Ci, utils: Cu, results: Cr} = Components;
+var {classes: Cc, interfaces: Ci, utils: Cu} = Components;
 const {require, loader} = Cu.import("resource://devtools/shared/Loader.jsm", {});
 const promise = require("promise");
 loader.lazyImporter(this, "Task", "resource://gre/modules/Task.jsm", "Task");
-const subScriptLoader = Cc["@mozilla.org/moz/jssubscript-loader;1"]
-                          .getService(Ci.mozIJSSubScriptLoader);
-var EventUtils = {};
-subScriptLoader.loadSubScript("chrome://marionette/content/EventUtils.js", EventUtils);
+
 loader.lazyGetter(this, "nsIProfilerModule", () => {
   return Cc["@mozilla.org/tools/profiler;1"].getService(Ci.nsIProfiler);
 });
 
 addMessageListener("devtools:test:history", function ({ data }) {
   content.history[data.direction]();
 });
 
@@ -176,30 +173,16 @@ addMessageListener("devtools:test:setAtt
   }
 
   node.setAttribute(attributeName, attributeValue);
 
   sendAsyncMessage("devtools:test:setAttribute");
 });
 
 /**
- * Synthesize a key event for an element. This handler doesn't send a message
- * back. Consumers should listen to specific events on the inspector/highlighter
- * to know when the event got synthesized.
- * @param  {Object} msg The msg.data part expects the following properties:
- * - {String} key
- * - {Object} options
- */
-addMessageListener("Test:SynthesizeKey", function(msg) {
-  let {key, options} = msg.data;
-
-  EventUtils.synthesizeKey(key, options, content);
-});
-
-/**
  * Like document.querySelector but can go into iframes too.
  * ".container iframe || .sub-container div" will first try to find the node
  * matched by ".container iframe" in the root document, then try to get the
  * content document inside it, and then try to match ".sub-container div" inside
  * this document.
  * Any selector coming before the || separator *MUST* match a frame node.
  * @param {String} superSelector.
  * @return {DOMNode} The node, or null if not found.

--- a/devtools/client/shared/test/test-actor.js
+++ b/devtools/client/shared/test/test-actor.js
@@ -8,18 +8,26 @@
 
 var { Cc, Ci, Cu, Cr } = require("chrome");
 const {getRect, getElementFromPoint, getAdjustedQuads} = require("devtools/shared/layout/utils");
 const promise = require("promise");
 const {Task} = Cu.import("resource://gre/modules/Task.jsm", {});
 var DOMUtils = Cc["@mozilla.org/inspector/dom-utils;1"].getService(Ci.inIDOMUtils);
 var loader = Cc["@mozilla.org/moz/jssubscript-loader;1"]
             .getService(Ci.mozIJSSubScriptLoader);
-var EventUtils = {};
-loader.loadSubScript("chrome://marionette/content/EventUtils.js", EventUtils);
+
+// Set up a dummy environment so that EventUtils works. We need to be careful to
+// pass a window object into each EventUtils method we call rather than having
+// it rely on the |window| global.
+let EventUtils = {};
+EventUtils.window = {};
+EventUtils.parent = {};
+EventUtils._EU_Ci = Components.interfaces;
+EventUtils._EU_Cc = Components.classes;
+loader.loadSubScript("chrome://mochikit/content/tests/SimpleTest/EventUtils.js", EventUtils);
 
 const protocol = require("devtools/server/protocol");
 const {Arg, Option, method, RetVal, types} = protocol;
 
 var dumpn = msg => {
   dump(msg + "\n");
 }