--- a/devtools/client/inspector/layout/test/browser_layout_editablemodel.js
+++ b/devtools/client/inspector/layout/test/browser_layout_editablemodel.js
@@ -25,17 +25,17 @@ add_task(function*() {
 
   yield runTests(inspector, view);
 });
 
 addTest("Test that editing margin dynamically updates the document, pressing escape cancels the changes",
 function*(inspector, view) {
   let node = content.document.getElementById("div1");
   is(getStyle(node, "margin-top"), "", "Should be no margin-top on the element.")
-  yield selectNode(node, inspector);
+  yield selectNode("#div1", inspector);
 
   let span = view.doc.querySelector(".margin.top > span");
   is(span.textContent, 5, "Should have the right value in the box model.");
 
   EventUtils.synthesizeMouseAtCenter(span, {}, view.doc.defaultView);
   let editor = view.doc.querySelector(".styleinspector-propertyeditor");
   ok(editor, "Should have opened the editor.");
   is(editor.value, "5px", "Should have the right value in the editor.");
@@ -51,17 +51,17 @@ function*(inspector, view) {
   is(getStyle(node, "margin-top"), "", "Should be no margin-top on the element.")
   is(span.textContent, 5, "Should have the right value in the box model.");
 });
 
 addTest("Test that arrow keys work correctly and pressing enter commits the changes",
 function*(inspector, view) {
   let node = content.document.getElementById("div1");
   is(getStyle(node, "margin-left"), "", "Should be no margin-top on the element.")
-  yield selectNode(node, inspector);
+  yield selectNode("#div1", inspector);
 
   let span = view.doc.querySelector(".margin.left > span");
   is(span.textContent, 10, "Should have the right value in the box model.");
 
   EventUtils.synthesizeMouseAtCenter(span, {}, view.doc.defaultView);
   let editor = view.doc.querySelector(".styleinspector-propertyeditor");
   ok(editor, "Should have opened the editor.");
   is(editor.value, "10px", "Should have the right value in the editor.");
@@ -88,17 +88,17 @@ function*(inspector, view) {
   is(getStyle(node, "margin-left"), "20px", "Should be the right margin-top on the element.")
   is(span.textContent, 20, "Should have the right value in the box model.");
 });
 
 addTest("Test that deleting the value removes the property but escape undoes that",
 function*(inspector, view) {
   let node = content.document.getElementById("div1");
   is(getStyle(node, "margin-left"), "20px", "Should be the right margin-top on the element.")
-  yield selectNode(node, inspector);
+  yield selectNode("#div1", inspector);
 
   let span = view.doc.querySelector(".margin.left > span");
   is(span.textContent, 20, "Should have the right value in the box model.");
 
   EventUtils.synthesizeMouseAtCenter(span, {}, view.doc.defaultView);
   let editor = view.doc.querySelector(".styleinspector-propertyeditor");
   ok(editor, "Should have opened the editor.");
   is(editor.value, "20px", "Should have the right value in the editor.");
@@ -118,17 +118,17 @@ function*(inspector, view) {
 
 addTest("Test that deleting the value removes the property",
 function*(inspector, view) {
   let node = content.document.getElementById("div1");
 
   node.style.marginRight = "15px";
   yield waitForUpdate(inspector);
 
-  yield selectNode(node, inspector);
+  yield selectNode("#div1", inspector);
 
   let span = view.doc.querySelector(".margin.right > span");
   is(span.textContent, 15, "Should have the right value in the box model.");
 
   EventUtils.synthesizeMouseAtCenter(span, {}, view.doc.defaultView);
   let editor = view.doc.querySelector(".styleinspector-propertyeditor");
   ok(editor, "Should have opened the editor.");
   is(editor.value, "15px", "Should have the right value in the editor.");

--- a/devtools/client/inspector/layout/test/browser_layout_editablemodel_allproperties.js
+++ b/devtools/client/inspector/layout/test/browser_layout_editablemodel_allproperties.js
@@ -27,17 +27,17 @@ add_task(function*() {
 
 addTest("When all properties are set on the node editing one should work",
 function*(inspector, view) {
   let node = content.document.getElementById("div1");
 
   node.style.padding = "5px";
   yield waitForUpdate(inspector);
 
-  yield selectNode(node, inspector);
+  yield selectNode("#div1", inspector);
 
   let span = view.doc.querySelector(".padding.bottom > span");
   is(span.textContent, 5, "Should have the right value in the box model.");
 
   EventUtils.synthesizeMouseAtCenter(span, {}, view.doc.defaultView);
   let editor = view.doc.querySelector(".styleinspector-propertyeditor");
   ok(editor, "Should have opened the editor.");
   is(editor.value, "5px", "Should have the right value in the editor.");
@@ -56,17 +56,17 @@ function*(inspector, view) {
 
 addTest("When all properties are set on the node editing one should work",
 function*(inspector, view) {
   let node = content.document.getElementById("div1");
 
   node.style.padding = "5px";
   yield waitForUpdate(inspector);
 
-  yield selectNode(node, inspector);
+  yield selectNode("#div1", inspector);
 
   let span = view.doc.querySelector(".padding.left > span");
   is(span.textContent, 5, "Should have the right value in the box model.");
 
   EventUtils.synthesizeMouseAtCenter(span, {}, view.doc.defaultView);
   let editor = view.doc.querySelector(".styleinspector-propertyeditor");
   ok(editor, "Should have opened the editor.");
   is(editor.value, "5px", "Should have the right value in the editor.");
@@ -85,17 +85,17 @@ function*(inspector, view) {
 });
 
 addTest("When all properties are set on the node deleting one should work",
 function*(inspector, view) {
   let node = content.document.getElementById("div1");
 
   node.style.padding = "5px";
 
-  yield selectNode(node, inspector);
+  yield selectNode("#div1", inspector);
 
   let span = view.doc.querySelector(".padding.left > span");
   is(span.textContent, 5, "Should have the right value in the box model.");
 
   EventUtils.synthesizeMouseAtCenter(span, {}, view.doc.defaultView);
   let editor = view.doc.querySelector(".styleinspector-propertyeditor");
   ok(editor, "Should have opened the editor.");
   is(editor.value, "5px", "Should have the right value in the editor.");
@@ -114,17 +114,17 @@ function*(inspector, view) {
 
 addTest("When all properties are set on the node deleting one then cancelling should work",
 function*(inspector, view) {
   let node = content.document.getElementById("div1");
 
   node.style.padding = "5px";
   yield waitForUpdate(inspector);
 
-  yield selectNode(node, inspector);
+  yield selectNode("#div1", inspector);
 
   let span = view.doc.querySelector(".padding.left > span");
   is(span.textContent, 5, "Should have the right value in the box model.");
 
   EventUtils.synthesizeMouseAtCenter(span, {}, view.doc.defaultView);
   let editor = view.doc.querySelector(".styleinspector-propertyeditor");
   ok(editor, "Should have opened the editor.");
   is(editor.value, "5px", "Should have the right value in the editor.");

--- a/devtools/client/inspector/layout/test/browser_layout_editablemodel_border.js
+++ b/devtools/client/inspector/layout/test/browser_layout_editablemodel_border.js
@@ -20,17 +20,17 @@ function getStyle(node, property) {
 
 add_task(function*() {
   yield addTab("data:text/html," + encodeURIComponent(TEST_URI));
   let {toolbox, inspector, view} = yield openLayoutView();
 
   let node = content.document.getElementById("div1");
   is(getStyle(node, "border-top-width"), "", "Should have the right border");
   is(getStyle(node, "border-top-style"), "", "Should have the right border");
-  yield selectNode(node, inspector);
+  yield selectNode("#div1", inspector);
 
   let span = view.doc.querySelector(".border.top > span");
   is(span.textContent, 0, "Should have the right value in the box model.");
 
   EventUtils.synthesizeMouseAtCenter(span, {}, view.doc.defaultView);
   let editor = view.doc.querySelector(".styleinspector-propertyeditor");
   ok(editor, "Should have opened the editor.");
   is(editor.value, "0", "Should have the right value in the editor.");

--- a/devtools/client/inspector/layout/test/browser_layout_editablemodel_stylerules.js
+++ b/devtools/client/inspector/layout/test/browser_layout_editablemodel_stylerules.js
@@ -25,17 +25,17 @@ add_task(function*() {
 
   yield runTests(inspector, view);
 });
 
 addTest("Test that entering units works",
 function*(inspector, view) {
   let node = content.document.getElementById("div1");
   is(getStyle(node, "padding-top"), "", "Should have the right padding");
-  yield selectNode(node, inspector);
+  yield selectNode("#div1", inspector);
 
   let span = view.doc.querySelector(".padding.top > span");
   is(span.textContent, 3, "Should have the right value in the box model.");
 
   EventUtils.synthesizeMouseAtCenter(span, {}, view.doc.defaultView);
   let editor = view.doc.querySelector(".styleinspector-propertyeditor");
   ok(editor, "Should have opened the editor.");
   is(editor.value, "3px", "Should have the right value in the editor.");
@@ -58,17 +58,17 @@ function*(inspector, view) {
   is(getStyle(node, "padding-top"), "1em", "Should be the right padding.")
   is(span.textContent, 16, "Should have the right value in the box model.");
 });
 
 addTest("Test that we pick up the value from a higher style rule",
 function*(inspector, view) {
   let node = content.document.getElementById("div2");
   is(getStyle(node, "border-bottom-width"), "", "Should have the right border-bottom-width");
-  yield selectNode(node, inspector);
+  yield selectNode("#div2", inspector);
 
   let span = view.doc.querySelector(".border.bottom > span");
   is(span.textContent, 16, "Should have the right value in the box model.");
 
   EventUtils.synthesizeMouseAtCenter(span, {}, view.doc.defaultView);
   let editor = view.doc.querySelector(".styleinspector-propertyeditor");
   ok(editor, "Should have opened the editor.");
   is(editor.value, "1em", "Should have the right value in the editor.");
@@ -84,17 +84,17 @@ function*(inspector, view) {
   is(getStyle(node, "border-bottom-width"), "0px", "Should be the right border-bottom-width.")
   is(span.textContent, 0, "Should have the right value in the box model.");
 });
 
 addTest("Test that shorthand properties are parsed correctly",
 function*(inspector, view) {
   let node = content.document.getElementById("div3");
   is(getStyle(node, "padding-right"), "", "Should have the right padding");
-  yield selectNode(node, inspector);
+  yield selectNode("#div3", inspector);
 
   let span = view.doc.querySelector(".padding.right > span");
   is(span.textContent, 32, "Should have the right value in the box model.");
 
   EventUtils.synthesizeMouseAtCenter(span, {}, view.doc.defaultView);
   let editor = view.doc.querySelector(".styleinspector-propertyeditor");
   ok(editor, "Should have opened the editor.");
   is(editor.value, "2em", "Should have the right value in the editor.");

--- a/devtools/client/inspector/layout/test/browser_layout_update-after-navigation.js
+++ b/devtools/client/inspector/layout/test/browser_layout_update-after-navigation.js
@@ -3,17 +3,17 @@
  http://creativecommons.org/publicdomain/zero/1.0/ */
 
 "use strict";
 
 // Test that the layout-view continues to work after a page navigation and that
 // it also works after going back
 
 add_task(function*() {
-  yield addTab(TEST_URL_ROOT + "doc_layout_iframe1.html");
+  yield addTab(URL_ROOT + "doc_layout_iframe1.html");
   let {toolbox, inspector, view} = yield openLayoutView();
   yield runTests(inspector, view);
 });
 
 addTest("Test that the layout-view works on the first page",
 function*(inspector, view) {
   info("Selecting the test node");
   yield selectNode("p", inspector);
@@ -29,17 +29,17 @@ function*(inspector, view) {
   ok(true, "Layout-view got updated");
 
   info("Checking that the layout-view shows the right value after update");
   is(paddingElt.textContent, "20");
 });
 
 addTest("Navigate to the second page",
 function*(inspector, view) {
-  yield navigateTo(TEST_URL_ROOT + "doc_layout_iframe2.html");
+  yield navigateTo(URL_ROOT + "doc_layout_iframe2.html");
   yield inspector.once("markuploaded");
 });
 
 addTest("Test that the layout-view works on the second page",
 function*(inspector, view) {
   info("Selecting the test node");
   yield selectNode("p", inspector);
 

--- a/devtools/client/inspector/layout/test/browser_layout_update-after-reload.js
+++ b/devtools/client/inspector/layout/test/browser_layout_update-after-reload.js
@@ -2,17 +2,17 @@
 /* Any copyright is dedicated to the Public Domain.
  http://creativecommons.org/publicdomain/zero/1.0/ */
 
 "use strict";
 
 // Test that the layout-view continues to work after the page is reloaded
 
 add_task(function*() {
-  yield addTab(TEST_URL_ROOT + "doc_layout_iframe1.html");
+  yield addTab(URL_ROOT + "doc_layout_iframe1.html");
   let {toolbox, inspector, view} = yield openLayoutView();
 
   info("Test that the layout-view works on the first page");
   yield assertLayoutView(inspector, view);
 
   info("Reload the page");
   content.location.reload();
   yield inspector.once("markuploaded");

--- a/devtools/client/inspector/layout/test/browser_layout_update-in-iframes.js
+++ b/devtools/client/inspector/layout/test/browser_layout_update-in-iframes.js
@@ -3,28 +3,28 @@
  http://creativecommons.org/publicdomain/zero/1.0/ */
 
 "use strict";
 
 // Test that the layout-view for elements within iframes also updates when they
 // change
 
 add_task(function*() {
-  yield addTab(TEST_URL_ROOT + "doc_layout_iframe1.html");
+  yield addTab(URL_ROOT + "doc_layout_iframe1.html");
   let iframe2 = getNode("iframe").contentDocument.querySelector("iframe");
 
   let {toolbox, inspector, view} = yield openLayoutView();
   yield runTests(inspector, view, iframe2);
 });
 
 addTest("Test that resizing an element in an iframe updates its box model",
 function*(inspector, view, iframe2) {
   info("Selecting the nested test node");
   let node = iframe2.contentDocument.querySelector("div");
-  yield selectNode(node, inspector);
+  yield selectNodeInIframe2("div", inspector);
 
   info("Checking that the layout-view shows the right value");
   let sizeElt = view.doc.querySelector(".size > span");
   is(sizeElt.textContent, "400x200");
 
   info("Listening for layout-view changes and modifying its size");
   let onUpdated = waitForUpdate(inspector);
   node.style.width = "200px";
@@ -38,23 +38,30 @@ function*(inspector, view, iframe2) {
 addTest("Test reflows are still sent to the layout-view after deleting an iframe",
 function*(inspector, view, iframe2) {
   info("Deleting the iframe2");
   iframe2.remove();
   yield inspector.once("inspector-updated");
 
   info("Selecting the test node in iframe1");
   let node = getNode("iframe").contentDocument.querySelector("p");
-  yield selectNode(node, inspector);
+  yield selectNodeInIframe2("p", inspector);
 
   info("Checking that the layout-view shows the right value");
   let sizeElt = view.doc.querySelector(".size > span");
   is(sizeElt.textContent, "100x100");
 
   info("Listening for layout-view changes and modifying its size");
   let onUpdated = waitForUpdate(inspector);
   node.style.width = "200px";
   yield onUpdated;
   ok(true, "Layout-view got updated");
 
   info("Checking that the layout-view shows the right value after update");
   is(sizeElt.textContent, "200x100");
 });
+
+function* selectNodeInIframe2(selector, inspector) {
+  let iframe1 = yield getNodeFront("iframe", inspector);
+  let iframe2 = yield getNodeFrontInFrame("iframe", iframe1, inspector);
+  let node = yield getNodeFrontInFrame(selector, iframe2, inspector);
+  yield selectNode(node, inspector);
+}

--- a/devtools/client/inspector/layout/test/head.js
+++ b/devtools/client/inspector/layout/test/head.js
@@ -1,86 +1,28 @@
 /* vim: set ft=javascript ts=2 et sw=2 tw=80: */
 /* Any copyright is dedicated to the Public Domain.
  http://creativecommons.org/publicdomain/zero/1.0/ */
-
 "use strict";
 
-var Cu = Components.utils;
-var {gDevTools} = Cu.import("resource://devtools/client/framework/gDevTools.jsm", {});
-var {require} = Cu.import("resource://devtools/shared/Loader.jsm", {});
-var {console} = Cu.import("resource://gre/modules/Console.jsm", {});
-var {TargetFactory} = require("devtools/client/framework/target");
-var promise = require("promise");
-var DevToolsUtils = require("devtools/shared/DevToolsUtils");
-
-// All test are asynchronous
-waitForExplicitFinish();
+// Import the inspector's head.js first (which itself imports shared-head.js).
+Services.scriptloader.loadSubScript(
+  "chrome://mochitests/content/browser/devtools/client/inspector/test/head.js",
+  this);
 
-const TEST_URL_ROOT =
-  "http://example.com/browser/devtools/client/inspector/layout/test/";
-
-// Uncomment this pref to dump all devtools emitted events to the console.
-// Services.prefs.setBoolPref("devtools.dump.emit", true);
-
-// Services.prefs.setBoolPref("devtools.debugger.log", true);
-
-// Set the testing flag on DevToolsUtils and reset it when the test ends
-DevToolsUtils.testing = true;
-registerCleanupFunction(() => DevToolsUtils.testing = false);
-
-// Clean-up all prefs that might have been changed during a test run
-// (safer here because if the test fails, then the pref is never reverted)
 Services.prefs.setIntPref("devtools.toolbox.footer.height", 350);
 registerCleanupFunction(() => {
-  Services.prefs.clearUserPref("devtools.dump.emit");
-  Services.prefs.clearUserPref("devtools.debugger.log");
   Services.prefs.clearUserPref("devtools.toolbox.footer.height");
-  Services.prefs.setCharPref("devtools.inspector.activeSidebar", "ruleview");
-});
-
-registerCleanupFunction(function*() {
-  let target = TargetFactory.forTab(gBrowser.selectedTab);
-  yield gDevTools.closeToolbox(target);
-
-  // Move the mouse outside inspector. If the test happened fake a mouse event
-  // somewhere over inspector the pointer is considered to be there when the
-  // next test begins. This might cause unexpected events to be emitted when
-  // another test moves the mouse.
-  EventUtils.synthesizeMouseAtPoint(1, 1, {type: "mousemove"}, window);
-
-  while (gBrowser.tabs.length > 1) {
-    gBrowser.removeCurrentTab();
-  }
 });
 
 /**
- * Add a new test tab in the browser and load the given url.
- * @param {String} url The url to be loaded in the new tab
- * @return a promise that resolves to the tab object when the url is loaded
- */
-function addTab(url) {
-  let def = promise.defer();
-
-  let tab = gBrowser.selectedTab = gBrowser.addTab();
-  gBrowser.selectedBrowser.addEventListener("load", function onload() {
-    gBrowser.selectedBrowser.removeEventListener("load", onload, true);
-    info("URL " + url + " loading complete into new test tab");
-    waitForFocus(() => {
-      def.resolve(tab);
-    }, content);
-  }, true);
-  content.location = url;
-
-  return def.promise;
-}
-
-/**
  * Simple DOM node accesor function that takes either a node or a string css
  * selector as argument and returns the corresponding node
+ * FIXME: Delete this function and use inspector/test/head.js' getNode instead,
+ * and fix all layout-view tests to use nodeFronts instead of CPOWs.
  * @param {String|DOMNode} nodeOrSelector
  * @return {DOMNode}
  */
 function getNode(nodeOrSelector) {
   return typeof nodeOrSelector === "string" ?
     content.document.querySelector(nodeOrSelector) :
     nodeOrSelector;
 }
@@ -99,102 +41,16 @@ function selectAndHighlightNode(nodeOrSe
 
   let node = getNode(nodeOrSelector);
   let updated = inspector.toolbox.once("highlighter-ready");
   inspector.selection.setNode(node, "test-highlight");
   return updated;
 }
 
 /**
- * Set the inspector's current selection to a node or to the first match of the
- * given css selector.
- * @param {String|DOMNode} nodeOrSelector
- * @param {InspectorPanel} inspector
- *        The instance of InspectorPanel currently loaded in the toolbox
- * @param {String} reason
- *        Defaults to "test" which instructs the inspector not to highlight the
- *        node upon selection
- * @return a promise that resolves when the inspector is updated with the new
- * node
- */
-function selectNode(nodeOrSelector, inspector, reason = "test") {
-  info("Selecting the node " + nodeOrSelector);
-
-  let node = getNode(nodeOrSelector);
-  let updated = inspector.once("inspector-updated");
-  inspector.selection.setNode(node, reason);
-  return updated;
-}
-
-/**
- * Open the toolbox, with the inspector tool visible.
- * @return a promise that resolves when the inspector is ready
- */
-var openInspector = Task.async(function*() {
-  info("Opening the inspector");
-  let target = TargetFactory.forTab(gBrowser.selectedTab);
-
-  let inspector, toolbox;
-
-  // The actual highligher show/hide methods are mocked in layoutview tests.
-  // The highlighter is tested in devtools/inspector/test.
-  function mockHighlighter({highlighter}) {
-    highlighter.showBoxModel = function(nodeFront, options) {
-      return promise.resolve();
-    };
-    highlighter.hideBoxModel = function() {
-      return promise.resolve();
-    };
-  }
-
-  // Checking if the toolbox and the inspector are already loaded
-  // The inspector-updated event should only be waited for if the inspector
-  // isn't loaded yet
-  toolbox = gDevTools.getToolbox(target);
-  if (toolbox) {
-    inspector = toolbox.getPanel("inspector");
-    if (inspector) {
-      info("Toolbox and inspector already open");
-      mockHighlighter(toolbox);
-      return {
-        toolbox: toolbox,
-        inspector: inspector
-      };
-    }
-  }
-
-  info("Opening the toolbox");
-  toolbox = yield gDevTools.showToolbox(target, "inspector");
-  yield waitForToolboxFrameFocus(toolbox);
-  inspector = toolbox.getPanel("inspector");
-
-  info("Waiting for the inspector to update");
-  yield inspector.once("inspector-updated");
-
-  mockHighlighter(toolbox);
-  return {
-    toolbox: toolbox,
-    inspector: inspector
-  };
-});
-
-/**
- * Wait for the toolbox frame to receive focus after it loads
- * @param {Toolbox} toolbox
- * @return a promise that resolves when focus has been received
- */
-function waitForToolboxFrameFocus(toolbox) {
-  info("Making sure that the toolbox's frame is focused");
-  let def = promise.defer();
-  let win = toolbox.frame.contentWindow;
-  waitForFocus(def.resolve, win);
-  return def.promise;
-}
-
-/**
  * Checks whether the inspector's sidebar corresponding to the given id already
  * exists
  * @param {InspectorPanel}
  * @param {String}
  * @return {Boolean}
  */
 function hasSideBarTab(inspector, id) {
   return !!inspector.sidebar.getWindowForTab(id);
@@ -204,16 +60,28 @@ function hasSideBarTab(inspector, id) {
  * Open the toolbox, with the inspector tool visible, and the layout-view
  * sidebar tab selected.
  * @return a promise that resolves when the inspector is ready and the layout
  * view is visible and ready
  */
 var openLayoutView = Task.async(function*() {
   let {toolbox, inspector} = yield openInspector();
 
+  // The actual highligher show/hide methods are mocked in layoutview tests.
+  // The highlighter is tested in devtools/inspector/test.
+  function mockHighlighter({highlighter}) {
+    highlighter.showBoxModel = function(nodeFront, options) {
+      return promise.resolve();
+    };
+    highlighter.hideBoxModel = function() {
+      return promise.resolve();
+    };
+  }
+  mockHighlighter(toolbox);
+
   if (!hasSideBarTab(inspector, "layoutview")) {
     info("Waiting for the layoutview sidebar to be ready");
     yield inspector.sidebar.once("layoutview-ready");
   }
 
   info("Selecting the layoutview sidebar");
   inspector.sidebar.select("layoutview");
 

--- a/devtools/client/inspector/test/head.js
+++ b/devtools/client/inspector/test/head.js
@@ -1,36 +1,38 @@
 /* vim: set ts=2 et sw=2 tw=80: */
 /* 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";
 
 // Load the shared-head file first.
 Services.scriptloader.loadSubScript(
-  "chrome://mochitests/content/browser/devtools/client/framework/test/shared-head.js", this);
+  "chrome://mochitests/content/browser/devtools/client/framework/test/shared-head.js",
+  this);
 
 // Services.prefs.setBoolPref("devtools.debugger.log", true);
 // SimpleTest.registerCleanupFunction(() => {
 //   Services.prefs.clearUserPref("devtools.debugger.log");
 // });
 
 // Uncomment this pref to dump all devtools emitted events to the console.
 // Services.prefs.setBoolPref("devtools.dump.emit", true);
 
 var ROOT_TEST_DIR = getRootDirectory(gTestPath);
 
 // Import the GCLI test helper
-var testDir = gTestPath.substr(0, gTestPath.lastIndexOf("/"));
 Services.scriptloader.loadSubScript(
-  testDir + "../../../commandline/test/helpers.js", this);
+  "chrome://mochitests/content/browser/devtools/client/commandline/test/helpers.js",
+  this);
 
 // Import helpers registering the test-actor in remote targets
 Services.scriptloader.loadSubScript(
-  testDir + "../../../shared/test/test-actor-registry.js", this);
+  "chrome://mochitests/content/browser/devtools/client/shared/test/test-actor-registry.js",
+  this);
 
 DevToolsUtils.testing = true;
 registerCleanupFunction(() => {
   DevToolsUtils.testing = false;
 });
 
 registerCleanupFunction(() => {
   Services.prefs.clearUserPref("devtools.dump.emit");