diff -r 000000000000 -r 6474c204b198 browser/devtools/responsivedesign/test/head.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/devtools/responsivedesign/test/head.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,123 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+let {devtools} = Cu.import("resource:///modules/devtools/gDevTools.jsm", {});
+let TargetFactory = devtools.TargetFactory;
+
+// Import the GCLI test helper
+let testDir = gTestPath.substr(0, gTestPath.lastIndexOf("/"));
+Services.scriptloader.loadSubScript(testDir + "../../../commandline/test/helpers.js", this);
+
+gDevTools.testing = true;
+SimpleTest.registerCleanupFunction(() => {
+  gDevTools.testing = false;
+});
+
+/**
+ * Open the toolbox, with the inspector tool visible.
+ * @return a promise that resolves when the inspector is ready
+ */
+let openInspector = Task.async(function*() {
+  info("Opening the inspector");
+  let target = TargetFactory.forTab(gBrowser.selectedTab);
+
+  let inspector, toolbox;
+
+  // 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");
+      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");
+
+  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;
+}
+
+/**
+ * Open the toolbox, with the inspector tool visible, and the sidebar that
+ * corresponds to the given id selected
+ * @return a promise that resolves when the inspector is ready and the sidebar
+ * view is visible and ready
+ */
+let openInspectorSideBar = Task.async(function*(id) {
+  let {toolbox, inspector} = yield openInspector();
+
+  if (!hasSideBarTab(inspector, id)) {
+    info("Waiting for the " + id + " sidebar to be ready");
+    yield inspector.sidebar.once(id + "-ready");
+  }
+
+  info("Selecting the " + id + " sidebar");
+  inspector.sidebar.select(id);
+
+  return {
+    toolbox: toolbox,
+    inspector: inspector,
+    view: inspector.sidebar.getWindowForTab(id)[id].view
+  };
+});
+
+/**
+ * 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);
+}
+
+/**
+ * Open the toolbox, with the inspector tool visible, and the computed-view
+ * sidebar tab selected.
+ * @return a promise that resolves when the inspector is ready and the computed
+ * view is visible and ready
+ */
+function openComputedView() {
+  return openInspectorSideBar("computedview");
+}
+
+/**
+ * Open the toolbox, with the inspector tool visible, and the rule-view
+ * sidebar tab selected.
+ * @return a promise that resolves when the inspector is ready and the rule
+ * view is visible and ready
+ */
+function openRuleView() {
+  return openInspectorSideBar("ruleview");
+}