<!DOCTYPE html>

<html>
<head>
    <script id="ui-script1" type="text/plain">
        (function() {
            var completions = 'Running UI-side script 1\n';
            
            uiController.doAsyncTask(function() {
                completions += 'Completed async task 1.1.\n';

                uiController.doAsyncTask(function() {
                    completions += 'Completed async task 1.2.\n';

                    uiController.doAsyncTask(function() {
                        completions += 'Completed async task 1.3. Script done.\n';

                        uiController.uiScriptComplete(completions);
                    });
                });
            });
        })();
    </script>

    <script id="ui-script2" type="text/plain">
        (function() {
            var completions2 = 'Running UI-side script 2\n';

            uiController.doAsyncTask(function() {
                completions2 += 'Completed async task 2.1. Script done.\n';

                uiController.uiScriptComplete(completions2);
            });
        })();
    </script>

    <script>
        if (window.testRunner) {
            testRunner.dumpAsText();
            testRunner.waitUntilDone();
        }

        let script1Result;
        let script2Result;

        var outstandingScripts = 2;
        function runTest()
        {
            if (testRunner.runUIScript) {
                var uiScript = document.getElementById('ui-script1').text;
                testRunner.runUIScript(uiScript, function(result) {
                    script1Result = result;
                    --outstandingScripts;
                    checkIfScriptsComplete();
                });

                var uiScript2 = document.getElementById('ui-script2').text;
                testRunner.runUIScript(uiScript2, function(result) {
                    script2Result = result;
                    --outstandingScripts;
                    checkIfScriptsComplete();
                });
            }
        }
        
        function checkIfScriptsComplete(remaining)
        {
            if (outstandingScripts)
                return;

            document.getElementById('results').textContent += 'Script 1:\n' + script1Result + 'Script 2:\n' + script2Result;

            testRunner.notifyDone();
        }

        window.addEventListener('load', runTest, false);
    </script>
</head>
<body>

<pre id="results"></pre>

</body>
</html>
.