Offer User Timing in workers

LayoutTests/fast/workers/resources/worker-performance.js

Index: LayoutTests/fast/workers/resources/worker-performance.js
diff --git a/LayoutTests/fast/workers/resources/worker-performance.js b/LayoutTests/fast/workers/resources/worker-performance.js
new file mode 100644
index 0000000000000000000000000000000000000000..49e2ca276a1343d631615f5dabbe0fd08734711a
--- /dev/null
+++ b/LayoutTests/fast/workers/resources/worker-performance.js
@@ -0,0 +1,34 @@
+var port = self.port || self;
+
+function assert_equals(actual, expected, description) {
+    if (actual == expected)
+        port.postMessage('PASS: ' + description);
+    else
+        port.postMessage('FAIL: ' + description + ': ' + actual + ' != ' + expected);
+}
+
+function assert_true(actual, description) {
+    if (actual)
+        port.postMessage('PASS: ' + description);
+    else
+        port.postMessage('FAIL: ' + description);
+}

[kinuko, 2015/06/04 08:21:22]

Could we also importScript LayoutTests/resources/testharness.js here?

(I found no worker tests are using that for now)

[Kunihiko Sakamoto, 2015/06/05 03:43:56]

Done, and merged into single testharness.js-based test used for all worker
types.

+
+performance.mark('startMark');
+setTimeout(timerFunc, 100);
+
+function timerFunc() {
+    performance.mark('endMark');
+    performance.measure('measure', 'startMark', 'endMark');
+
+    var startMark = performance.getEntriesByName('startMark')[0];
+    var endMark = performance.getEntriesByName('endMark')[0];
+    var measure = performance.getEntriesByType('measure')[0];
+
+    assert_equals(measure.startTime, startMark.startTime, 'startTime should match');
+    assert_true(measure.duration >= 100, 'measure.duration should be no less than 100ms');
+    assert_equals(performance.getEntriesByType('mark').length, 2, "getEntriesByType('mark')");
+    assert_equals(performance.getEntriesByType('measure').length, 1, "getEntriesByType('measure')");
+
+    port.postMessage('DONE');
+}