Use promises in notifications tests and enable controlling the page.

third_party/WebKit/LayoutTests/http/tests/notifications/resources/test-helpers.js

Index: third_party/WebKit/LayoutTests/http/tests/notifications/resources/test-helpers.js
diff --git a/third_party/WebKit/LayoutTests/http/tests/notifications/resources/test-helpers.js b/third_party/WebKit/LayoutTests/http/tests/notifications/resources/test-helpers.js
index fca5463c72841efe40fc2ad556868a9b1995d9ac..d9fb5a297c918da802fdda4a481b347cbe25e9b5 100644
--- a/third_party/WebKit/LayoutTests/http/tests/notifications/resources/test-helpers.js
+++ b/third_party/WebKit/LayoutTests/http/tests/notifications/resources/test-helpers.js
@@ -66,3 +66,38 @@ function getActiveServiceWorkerWithMessagePort(test, script, scope)
         });
     });
 }
+
+// Sends a message with |data| over |port|. Returns a promise that either rejects when a bad
+// response message is received, or otherwise resolves with the response data.
+function sendCommand(port, data)
+{
+    return new Promise((resolve, reject) => {
+        port.postMessage(data);
+        port.addEventListener('message', function listener(event) {
+            port.removeEventListener('message', listener);
+            if (typeof event.data != 'object' || !event.data.command) {
+                reject('Invalid message from the Service Worker.');

[Peter Beverloo, 2016/04/21 17:20:56]

nit: Promises should be rejected with errors.

new Error('Invalid message from the Service Worker.')

(Mentally map a rejection handler to the contents of the "catch" in a try {}
catch {}.)

[Michael van Ouwerkerk, 2016/04/22 09:44:22]

Done.

+            } else {
+                resolve(event.data);
+            }
+        });
+    });
+}
+
+// Simulates a click on the notification whose title equals |title|. The |actionIndex| specifies
+// which action button to activate, where -1 means the notification itself is clicked, not an action
+// button.
+function simulateNotificationClick(title, actionIndex, port)
+{
+    return new Promise((resolve, reject) => {
+        testRunner.simulateWebNotificationClick(title, actionIndex);
+        port.addEventListener('message', function listener(event) {
+            port.removeEventListener('message', listener);
+            if (typeof event.data != 'object' || event.data.command != 'click') {
+                reject('Invalid message from the Service Worker.');
+            } else {
+                resolve(event.data);
+            }
+        });
+    });
+}