Service Worker: Add worker client test for Clients.get(id)

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

 self.onfetch = function(e) {
-  if (e.request.url.indexOf('clients-get-frame.html') >= 0) {
+  if (e.request.url.indexOf('clients-get-frame.html') >= 0 ||
+      e.request.url.indexOf('clients-get-client-types') >= 0) {
     // On navigation, the client id should be null.
     if (e.clientId === null) {
       e.respondWith(fetch(e.request));
     } else {
       e.respondWith(Response.error());
     }
     return;
   }
   e.respondWith(new Response(e.clientId));
 };
@@ skipping 20 matching lines @@
                                 client.url,
                                 client.frameType]);
                 } else {
                   message.push(client);
                 }
               });
             port.postMessage(message);
           }
         }));
 };