Upstream service wrkr "window client" test to WPT

third_party/WebKit/LayoutTests/external/wpt/service-workers/service-worker/resources/windowclient-navigate-worker.js

+function match_query(query_string) {
+  return self.location.search.substr(1) == query_string;
+}
+
+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 locate 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);
+      });
+}
+
+function getTestClient() {
+  return clients.matchAll({ includeUncontrolled: true })
+    .then(function(client_list) {
+        var client, idx;

[falken, 2017/05/29 04:54:08]

nit: idx -> i for consistency with above

[mike3, 2017/05/29 17:00:49]

Done.

+
+        for (idx = 0; idx < client_list.length; ++idx) {

[falken, 2017/05/29 04:54:08]

nit: ++idx -> i++ for consistency with above

[mike3, 2017/05/29 17:00:50]

Done.

+          client = client_list[idx];
+
+          if (/windowclient-navigate\.https\.html/.test(client.url)) {
+            return client;
+          }
+        }
+
+        throw new Error('Service worker was unable to locate test client.');
+      });
+}
+
+function waitForMessage(client) {
+  var channel = new MessageChannel();
+  client.postMessage({ port: channel.port2 }, [channel.port2]);
+
+  return new Promise(function(resolve) {
+        channel.port1.onmessage = resolve;
+      });
+}
+
+// The worker must remain in the "installing" state for the duration of some
+// sub-tests. In order to achieve this coordination without relying on global
+// state, the worker must create a message channel with the client from within
+// the "install" event handler.
+if (match_query('installing')) {
+  self.addEventListener('install', function(e) {
+      e.waitUntil(getTestClient().then(waitForMessage));
+    });
+}
+
+self.addEventListener('message', function(e) {
+    e.waitUntil(navigate_test(e));
+  });