Noissue - Make test pages automation more reliable against timing issues

test/wrappers/pages.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-present eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 170 matching lines @@
                 if (title.startsWith("$popup Exception -"))
                 {
                   assert.equal(handles.length, 3, title);
                   return closeWindow(this.driver, handles[2], handles[1]);
                 }
 
                 assert.equal(handles.length, 2, title);
               });
             }
 
-            return takeScreenshot(element).then(screenshot =>
-              assert.ok(
+            return this.driver.wait(() =>
+              takeScreenshot(element).then(screenshot =>
                 screenshot.width == expectedScreenshot.width &&
                 screenshot.height == expectedScreenshot.height &&
                 screenshot.data.compare(expectedScreenshot.data) == 0,
-                title
-              )
+              ), 1000, title
             );
           });
         }
         return p2;
       });
     return p1;
   });
 });
 
 it("subscribe link", function()
@@ skipping 39 matching lines @@
         `)
       ).then(([added, err]) =>
       {
         if (err)
           throw err;
         assert.ok(added, "subscription added");
       })
     )
   );
 });