bindings: Fixes connect-helper to use stringifyDOMObject.

LayoutTests/http/tests/resources/testharness-helpers.js

Index: LayoutTests/http/tests/resources/testharness-helpers.js
diff --git a/LayoutTests/http/tests/resources/testharness-helpers.js b/LayoutTests/http/tests/resources/testharness-helpers.js
index d241ac0e4882222a01807c49510d786614eab4c4..4d7af1ff9ca77c85696f35368ff3a7a1c4b2480b 100644
--- a/LayoutTests/http/tests/resources/testharness-helpers.js
+++ b/LayoutTests/http/tests/resources/testharness-helpers.js
@@ -144,3 +144,20 @@ function assert_will_be_idl_attribute(object, attribute_name, description) {
 
   assert_true(attribute_name in object, description);
 }
+
+// Stringifies a DOM object.  This function stringifies not only own properties
+// but also DOM attributes which are on a prototype chain.  Note that
+// JSON.stringify only stringifies own properties.
+function stringifyDOMObject(object)
+{
+    function deepCopy(src) {
+        if (typeof src != "object")
+            return src;
+        var dst = Array.isArray(src) ? [] : {};
+        for (var property in src) {
+            dst[property] = deepCopy(src[property]);
+        }
+        return dst;
+    }
+    return JSON.stringify(deepCopy(object));
+}