Expose performance.memory in workers

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

 function runTests(event) {
   var tests = 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(results);
+  postMessage(JSON.stringify(results));

[sof, 2014/03/24 07:54:44]

Can be reverted.

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

[sof, 2014/03/24 07:54:44]

Can be reverted.

   };
 });