shaka-packager/tools/perf/measurements/page_cycler.js

62 lines
2.1 KiB
JavaScript

// Copyright (c) 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
(function() {
// The Mozilla DHTML performance tests need to explicitly call a function to
// trigger the next page visit, rather than directly using the onload handler.
// To meet needs of the DHTML performance tests without forking this head.js
// file, use a variable |__install_onload_handler| to indicate whether the
// |__onload| handler should be added to onload event listener.
// Install |__onload| by default if there is no pre-configuration.
if (typeof(__install_onload_handler) == 'undefined')
var __install_onload_handler = true;
// This is the timeout used in setTimeout inside the DHTML tests. Chrome has
// a much more accurate timer resolution than other browsers do. This results
// in Chrome running these tests much faster than other browsers. In order to
// compare Chrome with other browsers on DHTML performance alone, set this
// value to ~15.
var __test_timeout = 0;
function __set_cookie(name, value) {
document.cookie = name + "=" + value + "; path=/";
}
function __onbeforeunload() {
// Call GC twice to cleanup JS heap before starting a new test.
if (window.gc) {
window.gc();
window.gc();
}
}
// The function |__onload| is used by the DHTML tests.
window.__onload = function() {
// window.storeCreated is used by the Indexed DB tests.
if ((!__install_onload_handler || window.storeCreated) &&
!performance.timing.loadEventEnd)
return;
var unused = document.body.offsetHeight; // force layout
testComplete(window.performance.now());
};
// The function |testComplete| is used by the Indexed DB tests.
window.testComplete = function(time) {
window.__pc_load_time = time;
};
// The function |__eval_later| now is only used by the DHTML tests.
window.__eval_later = function(expression) {
setTimeout(expression, __test_timeout);
};
if (window.parent == window) { // Ignore subframes.
window.__pc_load_time = null;
addEventListener("load", __onload);
addEventListener("beforeunload", __onbeforeunload);
}
})();