The Tor Browser / file revision

 /* Any copyright is dedicated to the Public Domain.

    http://creativecommons.org/publicdomain/zero/1.0/ */

 const URL = "http://mochi.test:8888/browser/toolkit/components/thumbnails/" +

             "test/background_red_scroll.html";

 // Test for black borders caused by scrollbars.

 function runTests() {

   // Create a tab with a page with a red background and scrollbars.

   yield addTab(URL);

   yield captureAndCheckColor(255, 0, 0, "we have a red thumbnail");

   // Check the thumbnail color of the bottom right pixel.

   yield whenFileExists(URL);

   yield retrieveImageDataForURL(URL, function (aData) {

     let [r, g, b] = [].slice.call(aData, -4);

     is("" + [r,g,b], "255,0,0", "we have a red thumbnail");

     next();

   });

 }