Compatibility fix for Safari 6

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 1b62d327897997d632d87173d6d26f10d37e57f8..5c42d048773b9ef80f7e5b8a3c7ce46e10c0b8ad 100644
--- a/lib/compiler/implementation/lib/native_helper.dart
+++ b/lib/compiler/implementation/lib/native_helper.dart
@@ -10,6 +10,15 @@ String typeNameInChrome(obj) {
   return name;
 }
 
+String typeNameInSafari(obj) {
+  String name = constructorNameFallback(obj);
+  // Safari is very similar to Chrome.
+  if (name == 'Window') return 'DOMWindow';
+  if (name == 'CanvasPixelArray') return 'Uint8ClampedArray';
+  if (name == 'WebKitMutationObserver') return 'MutationObserver';
+  return name;
+}
+
 String typeNameInOpera(obj) {
   String name = constructorNameFallback(obj);
   if (name == 'Window') return 'DOMWindow';
@@ -84,6 +93,8 @@ Function getFunctionForTypeNameOf() {
     return typeNameInIE;
   } else if (userAgent.contains('Opera')) {
     return typeNameInOpera;
+  } else if (userAgent.contains('Safari')) {
+    return typeNameInSafari;
   } else {
     return constructorNameFallback;
   }