/**
 * Remove the `reftest-wait` class on the document element.
 * The reftest runner will wait with taking a screenshot while
 * this class is present.
 *
 * See https://web-platform-tests.org/writing-tests/reftests.html#controlling-when-comparison-occurs
 */
function takeScreenshot() {
    document.documentElement.classList.remove("reftest-wait");
}

/**
 * Call `takeScreenshot()` after a delay of at least |timeout| milliseconds.
 * @param {number} timeout - milliseconds
 */
function takeScreenshotDelayed(timeout) {
    setTimeout(function() {
        takeScreenshot();
    }, timeout);
}