--- a/testing/marionette/listener.js
+++ b/testing/marionette/listener.js
@@ -869,98 +869,104 @@ function multiAction(args, maxLen) {
 
   // now concurrent event is made of sets where each set contain a list of actions that need to be fired.
   // note: each action belongs to a different finger
   // pendingTouches keeps track of current touches that's on the screen
   let pendingTouches = [];
   setDispatch(concurrentEvent, pendingTouches);
 }
 
-/*
- * This implements the latter part of a get request (for the case we need to resume one
- * when a remoteness update happens in the middle of a navigate request). This is most of
- * of the work of a navigate request, but doesn't assume DOMContentLoaded is yet to fire.
+/**
+ * This implements the latter part of a get request (for the case we
+ * need to resume one when a remoteness update happens in the middle of a
+ * navigate request). This is most of of the work of a navigate request,
+ * but doesn't assume DOMContentLoaded is yet to fire.
  */
-function pollForReadyState(msg, start, callback) {
+function pollForReadyState(msg, start = undefined, callback = undefined) {
   let {pageTimeout, url, command_id} = msg.json;
-  start = start ? start : new Date().getTime();
-
+  if (!start) {
+    start = new Date().getTime();
+  }
   if (!callback) {
     callback = () => {};
   }
 
-  let end = null;
-  function checkLoad() {
+  let checkLoad = function() {
     navTimer.cancel();
-    end = new Date().getTime();
-    let aboutErrorRegex = /about:.+(error)\?/;
-    let elapse = end - start;
+
     let doc = curContainer.frame.document;
-    if (pageTimeout == null || elapse <= pageTimeout) {
+    let now = new Date().getTime();
+    if (pageTimeout == null || (now - start) <= pageTimeout) {
+      // document fully loaded
       if (doc.readyState == "complete") {
         callback();
         sendOk(command_id);
+
+      // we have reached an error url without requesting it
       } else if (doc.readyState == "interactive" &&
-                 aboutErrorRegex.exec(doc.baseURI) &&
-                 !doc.baseURI.startsWith(url)) {
-        // We have reached an error url without requesting it.
+          /about:.+(error)\?/.exec(doc.baseURI) &&
+          !doc.baseURI.startsWith(url)) {
         callback();
         sendError(new UnknownError("Error loading page"), command_id);
-      } else if (doc.readyState == "interactive" &&
-                 doc.baseURI.startsWith("about:")) {
+
+      // return early for about: urls
+      } else if (doc.readyState == "interactive" && doc.baseURI.startsWith("about:")) {
         callback();
         sendOk(command_id);
+
+      // document not fully loaded
       } else {
         navTimer.initWithCallback(checkLoad, 100, Ci.nsITimer.TYPE_ONE_SHOT);
       }
+
     } else {
       callback();
       sendError(new TimeoutError("Error loading page, timed out (checkLoad)"), command_id);
     }
-  }
+  };
   checkLoad();
 }
 
 /**
  * Navigate to the given URL.  The operation will be performed on the
  * current browsing context, which means it handles the case where we
  * navigate within an iframe.  All other navigation is handled by the
  * driver (in chrome space).
  */
 function get(msg) {
   let start = new Date().getTime();
 
   // Prevent DOMContentLoaded events from frames from invoking this
   // code, unless the event is coming from the frame associated with
   // the current window (i.e. someone has used switch_to_frame).
-  onDOMContentLoaded = function onDOMContentLoaded(event) {
-    if (!event.originalTarget.defaultView.frameElement ||
-        event.originalTarget.defaultView.frameElement == curContainer.frame.frameElement) {
+  let onLoad = function(event) {
+    let frameEl = event.originalTarget.defaultView.frameElement;
+    if (!frameEl || frameEl == curContainer.frame.frameElement) {
       pollForReadyState(msg, start, () => {
-        removeEventListener("DOMContentLoaded", onDOMContentLoaded, false);
+        removeEventListener("DOMContentLoaded", onLoad, false);
       });
     }
   };
 
-  function timerFunc() {
-    removeEventListener("DOMContentLoaded", onDOMContentLoaded, false);
-    sendError(new TimeoutError("Error loading page, timed out (onDOMContentLoaded)"), msg.json.command_id);
-  }
-  if (msg.json.pageTimeout != null) {
-    navTimer.initWithCallback(timerFunc, msg.json.pageTimeout, Ci.nsITimer.TYPE_ONE_SHOT);
+  if (msg.json.pageTimeout) {
+    let onTimeout = function() {
+      removeEventListener("DOMContentLoaded", loadEv, false);
+      sendError(new TimeoutError("Error loading page, timed out (onDOMContentLoaded)"), msg.json.command_id);
+    };
+    navTimer.initWithCallback(onTimeout, msg.json.pageTimeout, Ci.nsITimer.TYPE_ONE_SHOT);
   }
-  addEventListener("DOMContentLoaded", onDOMContentLoaded, false);
-  if (isB2G) {
-    curContainer.frame.location = msg.json.url;
-  } else {
-    // We need to move to the top frame before navigating
-    sendSyncMessage("Marionette:switchedToFrame", { frameValue: null });
+
+  addEventListener("DOMContentLoaded", onLoad, false);
+
+  // in Firefox we need to move to the top frame before navigating
+  if (!isB2G) {
+    sendSyncMessage("Marionette:switchedToFrame", {frameValue: null});
     curContainer.frame = content;
-    curContainer.frame.location = msg.json.url;
   }
+  curContainer.frame.location = msg.json.url;
 }
 
  /**
  * Cancel the polling and remove the event listener associated with a current
  * navigation request in case we're interupted by an onbeforeunload handler
  * and navigation doesn't complete.
  */
 function cancelRequest() {
@@ -1300,17 +1306,17 @@ function switchToShadowRoot(id) {
    let command_id = msg.json.command_id;
    curContainer.frame = curContainer.frame.parent;
    let parentElement = seenEls.add(curContainer.frame);
 
    sendSyncMessage(
        "Marionette:switchedToFrame", {frameValue: parentElement});
 
    sendOk(msg.json.command_id);
- }
+}
 
 /**
  * Switch to frame given either the server-assigned element id,
  * its index in window.frames, or the iframe's name or id.
  */
 function switchToFrame(msg) {
   let command_id = msg.json.command_id;
   function checkLoad() {