Reapply revision 11570, custom callbacks are now implemented in dartium.

lib/compiler/implementation/lib/native_helper.dart

Index: lib/compiler/implementation/lib/native_helper.dart
diff --git a/lib/compiler/implementation/lib/native_helper.dart b/lib/compiler/implementation/lib/native_helper.dart
index 7a9a3a13903a47e6f1072fd7195b3aadf21e38d7..aca2538319cee5f779bb74d432943270e81c3796 100644
--- a/lib/compiler/implementation/lib/native_helper.dart
+++ b/lib/compiler/implementation/lib/native_helper.dart
@@ -7,6 +7,7 @@ String typeNameInChrome(obj) {
   if (name == 'Window') return 'DOMWindow';
   if (name == 'CanvasPixelArray') return 'Uint8ClampedArray';
   if (name == 'WebKitMutationObserver') return 'MutationObserver';
+  if (name == 'FormData') return 'DOMFormData';
   return name;
 }
 
@@ -16,12 +17,14 @@ String typeNameInSafari(obj) {
   if (name == 'Window') return 'DOMWindow';
   if (name == 'CanvasPixelArray') return 'Uint8ClampedArray';
   if (name == 'WebKitMutationObserver') return 'MutationObserver';
+  if (name == 'FormData') return 'DOMFormData';
   return name;
 }
 
 String typeNameInOpera(obj) {
   String name = JS('String', '#', constructorNameFallback(obj));
   if (name == 'Window') return 'DOMWindow';
+  if (name == 'FormData') return 'DOMFormData';
   return name;
 }
 
@@ -33,6 +36,7 @@ String typeNameInFirefox(obj) {
   if (name == 'WorkerMessageEvent') return 'MessageEvent';
   if (name == 'DragEvent') return 'MouseEvent';
   if (name == 'DataTransfer') return 'Clipboard';
+  if (name == 'FormData') return 'DOMFormData';
   return name;
 }
 
@@ -55,6 +59,7 @@ String typeNameInIE(obj) {
   if (name == 'HTMLPhraseElement') return 'HTMLElement';
   if (name == 'MSStyleCSSProperties') return 'CSSStyleDeclaration';
   if (name == 'MouseWheelEvent') return 'WheelEvent';
+  if (name == 'FormData') return 'DOMFormData';
   return name;
 }