Support performance.now() in workers.

LayoutTests/http/tests/w3c/webperf/resources/worker.js

Index: LayoutTests/http/tests/w3c/webperf/resources/worker.js
diff --git a/LayoutTests/http/tests/w3c/webperf/resources/worker.js b/LayoutTests/http/tests/w3c/webperf/resources/worker.js
new file mode 100644
index 0000000000000000000000000000000000000000..cef7fc71bb3638e6231d6f758a48e2ec03f6bcae
--- /dev/null
+++ b/LayoutTests/http/tests/w3c/webperf/resources/worker.js
@@ -0,0 +1,26 @@
+function runTests(event) {
+  var tests = JSON.parse(event.data);
+  var results = [];
+  for (var i = 0; i < tests.length; i++) {
+    try {
+      results.push(eval(tests[i]));
+    } catch(e) {
+      results.push(e);
+    }
+  }
+  return results;
+}
+
+self.onmessage = function(event) {
+  var results = runTests(event);
+  postMessage(JSON.stringify(results));

[abarth-chromium, 2013/06/12 23:11:41]

You probably don't need to use JSON encoding here.  postMessage can structured
clone the objects for you.

[James Simonsen, 2013/06/13 00:01:36]

Oh nice. Thanks.

+  self.close();
+};
+
+self.addEventListener("connect", function(event) {
+  var port = event.ports[0];
+  port.onmessage = function(event) {
+    var results = runTests(event);
+    port.postMessage(JSON.stringify(results));
+  };
+});