fixes Polymer/polymer#725, unwrap FormData in XHR.send if needed

Author: John Messerly

build.json

@@ -46,5 +46,6 @@
   "src/wrappers/Window.js",
   "src/wrappers/DataTransfer.js",
   "src/wrappers/FormData.js",
+  "src/wrappers/XMLHttpRequest.js",
   "src/wrappers/override-constructors.js"
 ]

shadowdom.js

@@ -62,6 +62,7 @@
     'src/wrappers/Window.js',
     'src/wrappers/DataTransfer.js',
     'src/wrappers/FormData.js',
+    'src/wrappers/XMLHttpRequest.js',
     'src/wrappers/override-constructors.js'
   ].forEach(function(src) {
     document.write('<script src="' + base + src + '"></script>');

src/wrappers/XMLHttpRequest.js

@@ -0,0 +1,19 @@
+/*
+ * Copyright 2014 The Polymer Authors. All rights reserved.
+ * Use of this source code is goverened by a BSD-style
+ * license that can be found in the LICENSE file.
+ */
+
+(function(scope) {
+  'use strict';
+
+  var unwrapIfNeeded = scope.unwrapIfNeeded;
+  var originalSend = XMLHttpRequest.prototype.send;
+
+  // Since we only need to adjust XHR.send, we just patch it instead of wrapping
+  // the entire object. This happens when FormData is passed.
+  XMLHttpRequest.prototype.send = function(obj) {
+    return originalSend.call(this, unwrapIfNeeded(obj));
+  };
+
+})(window.ShadowDOMPolyfill);

test/js/XMLHttpRequest.js

@@ -0,0 +1,23 @@
+/*
+ * Copyright 2014 The Polymer Authors. All rights reserved.
+ * Use of this source code is goverened by a BSD-style
+ * license that can be found in the LICENSE file.
+ */
+
+suite('XMLHttpRequest', function() {
+
+  var wrap = ShadowDOMPolyfill.wrap;
+  var unwrap = ShadowDOMPolyfill.unwrap;
+
+  test('instanceof', function() {
+    var xhr = new XMLHttpRequest();
+    assert.instanceOf(xhr, XMLHttpRequest);
+  });
+
+  test('send', function() {
+    var xhr = new XMLHttpRequest();
+    xhr.open('POST', location.href);
+    xhr.send(new FormData());
+  });
+
+});

test/test.main.js

@@ -124,6 +124,7 @@ var modules = [
   'TouchEvent.js',
   'TreeScope.js',
   'Window.js',
+  'XMLHttpRequest.js',
   'build-json.js',
   'createTable.js',
   'custom-element.js',