Revert of ServiceWorker: throw when close() or terminate() called

LayoutTests/http/tests/serviceworker/resources/fetch-worker.js

 self.onmessage = function(e) {
     var message = e.data;
     if ('port' in message) {
         port = message.port;
         doNextFetchTest(port);
     }
 };
 
 var testTargets = [
     'other.html',
     'http://',
     'http://www.example.com/foo',
     'fetch-status.php?status=200',
     'fetch-status.php?status=404'
 ];
 
 function doNextFetchTest(port) {
-
-    function runInfiniteFetchLoop() {
-      fetch('dummy.html')
-        .then(function() { runInfiniteFetchLoop(); });
-    }
-
     if (testTargets.length == 0) {
-      // Destroying the execution context while fetch is happening
-      // should not cause a crash.
-      runInfiniteFetchLoop();
-
-      port.postMessage('quit');
-      return;
+        port.postMessage('quit');
+        // Destroying the execution context while fetch is happening should not cause a crash.
+        fetch('dummy.html').then(function() {}).catch(function() {});
+        self.close();
+        return;
     }
     var target = testTargets.shift();
     fetch(target)
     .then(function(response) {
         port.postMessage('Resolved: ' + target + ' [' + response.status + ']' + response.statusText);
         doNextFetchTest(port);
     }).catch(function(e) {
         port.postMessage('Rejected: ' + target + ' : '+ e.message);
         doNextFetchTest(port);
     });
 };