ServiceWorker: Rewrite windowclient-navigate.html test.

third_party/WebKit/LayoutTests/http/tests/serviceworker/resources/windowclient-navigate-worker.js

-var port = null;
+function match_query(query_string) {
+  return self.location.search.substr(1) == query_string;
+}
 
-self.onmessage = function(e) {
-  port = e.data.port;
-  port.onmessage = on_message;
-  port.postMessage('ready');
-};
-
-function on_message(e) {
-  var url = e.data;
-  var client;
-
-  self.clients.matchAll({ includeUncontrolled : true }).then(function(cs) {
-        cs.forEach(function(c) { c.frameType == 'nested' && (client = c); });
-        return client.navigate(url);
-      })
-    .then(function(c) {
-        if (!c)
-          port.postMessage(c);
-        else
-          port.postMessage(c.url);
-      })
-    .catch(function(e) {
-        port.postMessage(e.name);
+function receive_event(event_name) {
+  return new Promise(function(resolve) {
+        self.addEventListener(event_name, resolve, false);
       });
 }
+
+function get_test_data() {
+  return receive_event('message');
+}
+
+function navigate_test(e) {
+  var port = e.data.port;
+  var url = e.data.url;
+
+  return clients.matchAll({ includeUncontrolled : true })
+    .then(function(client_list) {
+        for (var i = 0; i < client_list.length; i++) {
+          var client = client_list[i];
+          if (client.frameType == 'nested') {
+            return client.navigate(url);
+          }
+        }
+        port.postMessage('Could not found window client.');
+      })
+    .then(function(new_client) {
+        if (new_client === null)
+          port.postMessage(new_client);
+        else
+          port.postMessage(new_client.url);
+      })
+    .catch(function(error) {
+        port.postMessage(error.name);
+      });
+}
+
+receive_event('install').then(function(e) {
+  if (match_query('installing'))
+    e.waitUntil(get_test_data().then(navigate_test));
+});
+
+receive_event('activate').then(function(e) {
+  if (match_query('activating')) {
+    // TODO(zino): Should do test in this case.
+  }
+  get_test_data().then(navigate_test);

[nhiroki, 2016/02/01 07:13:55]

Hmmm... there could be deadlock.

e.waitUntil(get_test_data()) waits for a message from the test html and the
'activate' event does not finish until the message arrives. On the other hand,
the test html waits for that the worker is activated, and it never happens
because the worker cannot finish the 'activate' event.

Possible solutions would be...

(1) using FetchEvent to wait for the completion of navigate() instead of
ActivateEvent, or
(2) deferring implementing this test until ExtendableMessageEvent is implemented
(http://crbug.com/543198)

[zino, 2016/02/02 15:58:31]

I have some questions.

(1) Can the fetch event be fired before worker's state is activated?
(2) about deadlock, yes, but I don't know why it happen exactly.
Is there a race condition between iframe loading and worker activating?
While the iframe loading happens on main thread, I think the work might run on
worker thread?
I uploaded another test code. (https://codereview.chromium.org/1643823003/)
If you run the test, you can see the 'console.log(state)' at developer console
but you can't see the 'console.log(frame)'.
I'm not sure but shouldn't the with_iframe(scope) has to resolve at least?
(FYI, in windowclient-navigate.html, I used wait_state('activating').)

[nhiroki, 2016/02/08 04:37:15]

No. When the worker is in installed/activating state, the fetch event is queued
up until the worker is activated. See the following links:
https://code.google.com/p/chromium/codesearch#chromium/src/content/browser/se...
https://code.google.com/p/chromium/codesearch#chromium/src/content/browser/se...

If you'd like to use the fetch event to wait for the completion of navigating
"in-scope-but-not-controlled-yet" client, you might need to create a frame
before registering a service worker and then navigate the frame after the worker
is activated.

FYI: ExtendableMessageEvent will be available in LayoutTests very soon:
http://crrev.com/1658073002/
Sorry, in my previous reply, I assumed that 'activated' was passed to
wait_for_state(). At any rate, as I commented on (1), iframe loading is blocked
until the worker is activated and deadlock happens.

+});
+