Backed out 2 changesets (bug 1658696) for perma failures on test_reftest.py. CLOSED TREE

Backed out changeset c8a6c4e4fb9f (bug 1658696)
Backed out changeset 2125e2962dcb (bug 1658696)

testing/marionette/reftest.js

@@ -136,7 +136,7 @@ reftest.Runner = class {
         commandID: this.driver.listener.activeMessageId,
         pageTimeout: timeout,
         url: "about:blank",
-        loadEventExpected: true,
+        loadEventExpected: false,
       });
     } else {
       logger.debug("Using separate window");
@@ -146,8 +146,6 @@ reftest.Runner = class {
       reftestWin = await this.openWindow(width, height);
     }
 
-    this.lastURL = this.driver.currentURL.href;
-
     this.setupWindow(reftestWin, width, height);
     this.windowUtils = reftestWin.windowUtils;
     this.reftestWin = reftestWin;