BrowserTest for delivering push message to service worker.

chrome/test/data/push_messaging/service_worker.js

Index: chrome/test/data/push_messaging/service_worker.js
diff --git a/chrome/test/data/push_messaging/service_worker.js b/chrome/test/data/push_messaging/service_worker.js
index 116b355671ff082a20266841e8ebf2d2a6726a1a..69f56461627579129304e02217b3aa383b3aa024 100644
--- a/chrome/test/data/push_messaging/service_worker.js
+++ b/chrome/test/data/push_messaging/service_worker.js
@@ -2,6 +2,24 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Empty service worker script.
+this.onmessage = function(event) {
+  console.log(event);
+  console.log(event.data);
+  sendDataToClients('Message from service worker.');
+};
 
-// TODO(mvanouwerkerk): Add test coverage for push event delivery.
+this.onpush = function(event) {
+  console.log(event);
+  console.log(event.data);
+  sendDataToClients(event.data);
+};
+
+function sendDataToClients(data) {
+  this.clients.getAll().then(function(clients) {
+    clients.forEach(function(client) {
+      client.postMessage(data);
+    });
+  }, function(error) {
+    console.log(error);
+  });
+}