Improve <adview> implementation and add tests.

chrome/test/data/extensions/platform_apps/ad_view/onloadcommit_ack/chrometest.js

Index: chrome/test/data/extensions/platform_apps/ad_view/onloadcommit_ack/chrometest.js
diff --git a/chrome/test/data/extensions/platform_apps/ad_view/onloadcommit_ack/chrometest.js b/chrome/test/data/extensions/platform_apps/ad_view/onloadcommit_ack/chrometest.js
new file mode 100644
index 0000000000000000000000000000000000000000..e66bf4388c547ba6a5b66a733ddc0757d6494cab
--- /dev/null
+++ b/chrome/test/data/extensions/platform_apps/ad_view/onloadcommit_ack/chrometest.js
@@ -0,0 +1,39 @@
+// Copyright (c) 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// This test checks the page loaded inside an <adview> has the ability to
+// 1) receive "message" events from the application, and 2) use
+// "window.postMessage" to post back a message to the application.
+
+function runTests(guestURL) {
+  chrome.test.runTests([
+    function test() {
+      var adview = document.getElementsByTagName("adview")[0];
+
+      adview.addEventListener("loadcommit", function() {
+        adview.contentWindow.postMessage({
+          message: "onloadcommit",
+          data: "data"
+        }, "*");
+      })
+
+      adview.setAttribute("src", guestURL);
+
+      window.addEventListener("message", function(event) {

[benwells, 2013/04/03 02:40:03]

Move adding the event listener to before setting the attribute. It is clearer
then that the set attribute triggers the flow of calls and callbacks.

[rpaquay, 2013/04/03 18:30:05]

Done.

+        if (event.data.message == "onloadcommit-ack") {
+          console.log("onloadcommit-ack message received.");
+          chrome.test.succeed();
+        }
+      })
+    }
+  ]);
+}
+
+window.onload = function() {
+  chrome.test.getConfig(function(config) {
+    var guestURL = 'http://localhost:' + config.testServer.port +
+        '/files/extensions/platform_apps/ad_view/ad_network_site/testsdk.html';
+    runTests(guestURL);
+  });
+}