Layout Tests: Remove stringifyDOMObject() helper

third_party/WebKit/LayoutTests/http/tests/notifications/instrumentation-service-worker.js

-importScripts('/resources/testharness-helpers.js');
-
-// For copying Notification.data. Currently a deep copy algorithm is used. Note
-// that the robustness of this function (and also |assert_object_equals| in
+// Deep-copies the attributes of |notification|. Note that the
+// robustness of this function (and also |assert_object_equals| in
 // testharness.js) affects the types of possible testing can be done.
 // TODO(peter): change this to a structured clone algorithm.
-function cloneObject(src) {
-    if (typeof src != 'object' || src === null)
-        return src;
-    var dst = Array.isArray(src) ? [] : {};
-    for (var property in src) {
-        if (src.hasOwnProperty(property))
-            dst[property] = cloneObject(src[property]);
+function cloneNotification(notification) {
+    function deepCopy(src) {
+        if (typeof src !== 'object' || src === null)
+            return src;
+        var dst = Array.isArray(src) ? [] : {};
+        for (var property in src) {
+            if (typeof src[property] === 'function')
+                continue;
+            dst[property] = deepCopy(src[property]);
+        }
+        return dst;
     }
-    return dst;
-}
 
-// Copies the serializable attributes of |notification|.
-function cloneNotification(notification) {
-    var copiedNotification = JSON.parse(stringifyDOMObject(notification));
-    copiedNotification.data = cloneObject(notification.data);
-    return copiedNotification;
+    return deepCopy(notification);
 }
 
 // Allows a document to exercise the Notifications API within a service worker by sending commands.
 var messagePort = null;
 
 // All urls of requests that have been routed through the fetch event handler.
 var fetchHistory = [];
 
 addEventListener('install', event => {
     event.waitUntil(skipWaiting());
@@ skipping 89 matching lines @@
 addEventListener('notificationclose', event => {
     var notificationCopy = cloneNotification(event.notification);
     messagePort.postMessage({ command: 'close',
                               notification: notificationCopy });
 });
 
 addEventListener('fetch', event => {
     fetchHistory.push(event.request.url);
     event.respondWith(fetch(event.request));
 });