Upstream foreign fetch tests.

third_party/WebKit/LayoutTests/http/tests/serviceworker/resources/foreign-fetch-event-worker.js

-self.addEventListener('install', function(event) {
-    test(function() {
-        assert_throws(new TypeError(), function() {
-            new ForeignFetchEvent('type');
-          });
-      }, 'ForeignFetchEvent constructor with no init dict');
-
-    test(function() {
-        assert_throws(new TypeError(), function() {
-            new ForeignFetchEvent('type', {});
-          });
-      }, 'ForeignFetchEvent constructor with empty init dict');
-
-    test(function() {
-        assert_throws(new TypeError(), function() {
-            new ForeignFetchEvent('type', { request: null });
-          });
-      }, 'ForeignFetchEvent constructor with null request');
-
-    test(function() {
-        var request = new Request('https://www.example.com/');
-        var event = new ForeignFetchEvent('type', { request: request, origin: 'origin' });
-        assert_equals(event.type, 'type');
-        assert_equals(event.request, request);
-        assert_equals(event.origin, 'origin');
-      }, 'ForeignFetchEvent constructor with all init dict members');
-  });
-
-// Import testharness after install handler to make sure our install handler
-// runs first. Otherwise only one test will run.
-importScripts('../../resources/testharness.js');