Bug 834266 - Use isEqualNode instead of == for comparing frames, r=mdas, a=test-only

testing/marionette/marionette-elements.js

@@ -98,7 +98,7 @@ ElementManager.prototype = {
       throw new ElementException("Element has not been seen before", 17, null);
     }
     el = el;
-    if (!(el.ownerDocument == win.document)) {
+    if (!(el.ownerDocument.isEqualNode(win.document))) {
       throw new ElementException("Stale element reference", 10, null);
     }
     return el;

testing/marionette/marionette-listener.js

@@ -1369,7 +1369,7 @@ function switchToFrame(msg) {
     if (elementManager.seenItems[msg.json.element] != undefined) {
       let wantedFrame = elementManager.getKnownElement(msg.json.element, curWindow); //HTMLIFrameElement
       for (let i = 0; i < frames.length; i++) {
-        if (frames[i] == wantedFrame) {
+        if (frames[i].isEqualNode(wantedFrame)) {
           curWindow = frames[i]; 
           foundFrame = i;
         }