Upstream service worker `client` tests to WPT

third_party/WebKit/LayoutTests/http/tests/serviceworker/resources/clients-matchall-worker.js

-self.onmessage = function(e) {
-  var port = e.data.port;
-  var options = e.data.options;
-
-  e.waitUntil(self.clients.matchAll(options).then(function(clients) {
-      var message = [];
-      clients.forEach(function(client) {
-          message.push([client.visibilityState,
-                        client.focused,
-                        client.url,
-                        client.frameType]);
-        });
-      port.postMessage(message);
-    }));
-};