ServiceWorker: Modernize postMessage tests for cleanup

third_party/WebKit/LayoutTests/http/tests/serviceworker/resources/postmessage-msgport-to-client-worker.js

Index: third_party/WebKit/LayoutTests/http/tests/serviceworker/resources/postmessage-msgport-to-client-worker.js
diff --git a/third_party/WebKit/LayoutTests/http/tests/serviceworker/resources/postmessage-msgport-to-client-worker.js b/third_party/WebKit/LayoutTests/http/tests/serviceworker/resources/postmessage-msgport-to-client-worker.js
index 4eb14ee1c41337b805f2ce65186b0f8b21219380..7af935f4f8fc01756980e46dcce5018ddc620e67 100644
--- a/third_party/WebKit/LayoutTests/http/tests/serviceworker/resources/postmessage-msgport-to-client-worker.js
+++ b/third_party/WebKit/LayoutTests/http/tests/serviceworker/resources/postmessage-msgport-to-client-worker.js
@@ -3,18 +3,17 @@ self.onmessage = function(e) {
       clients.forEach(function(client) {
           var messageChannel = new MessageChannel();
           messageChannel.port1.onmessage =
-            onMessageViaMessagePort.bind(null, client);
-          client.postMessage({port: messageChannel.port2},
-                             [messageChannel.port2]);
+            onMessageViaMessagePort.bind(null, messageChannel.port1);
+          client.postMessage(undefined, [messageChannel.port2]);
         });
     }));
 };
 
-function onMessageViaMessagePort(client, e) {
+function onMessageViaMessagePort(port, e) {
   var message = e.data;
   if ('value' in message) {
-    client.postMessage({ack: 'Acking value: ' + message.value});
+    port.postMessage({ack: 'Acking value: ' + message.value});
   } else if ('done' in message) {
-    client.postMessage({done: true});
+    port.postMessage({done: true});
   }
 }