diff -r 000000000000 -r 6474c204b198 browser/metro/base/tests/mochiperf/browser_tabs_01.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/metro/base/tests/mochiperf/browser_tabs_01.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,48 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+function test() {
+  runTests();
+}
+
+function timeTab(aUrl) {
+  return Task.spawn(function() {
+    let stopwatch = new StopWatch(true);
+    let tab = Browser.addTab(aUrl, true);
+    yield tab.pageShowPromise;
+    stopwatch.stop();
+    Browser.closeTab(tab, { forceClose: true })
+    yield waitForMs(500);
+    throw new Task.Result(stopwatch.time());
+  });
+}
+
+gTests.push({
+  desc: "tab open",
+  run: function run() {
+    yield addTab("about:blank");
+    yield hideContextUI();
+    yield waitForMs(5000);
+
+    let openDataSet = new Array();
+    for (let idx = 0; idx < 20; idx++) {
+      let time = yield timeTab("about:blank");
+      openDataSet.push(time);
+    }
+
+    // Give the browser a little time to clean up its tabs. 2 because
+    // we open a tab above as a base to get rid of the start screen.
+    yield waitForCondition(() => Browser.tabs.length == 2);
+    
+    PerfTest.declareTest("FBD7A532-D63A-44B5-9744-5CB07CFD131A",
+                         "tab open", "browser", "ux",
+                         "Open twenty tabs in succession, closing each before the next is opened. " +
+                         "Gives the browser time to settle in between. Lets the ui react however it " +
+                         "is designed to. Strips outliers.");
+    let result = PerfTest.computeAverage(openDataSet, { stripOutliers: true });
+    PerfTest.declareNumericalResult(result, "msec");
+  }
+});
+