Big merge from experimental to bleeding edge.

pkg/intl/lib/src/intl_helpers.dart

Index: pkg/intl/lib/src/intl_helpers.dart
diff --git a/pkg/intl/lib/src/intl_helpers.dart b/pkg/intl/lib/src/intl_helpers.dart
index 12c8395fd33cf3a1437e0f6417308b6dabe28b7c..d431584fdea98f2384c5aa1fe6e7279e483600d9 100644
--- a/pkg/intl/lib/src/intl_helpers.dart
+++ b/pkg/intl/lib/src/intl_helpers.dart
@@ -10,6 +10,8 @@
 library intl_helpers;
 import '../date_symbols.dart';
 
+import 'dart:async';
+
 /**
  * This is used as a marker for a locale data map that hasn't been initialized,
  * and will throw an exception on any usage that isn't the fallback
@@ -61,4 +63,4 @@ void initializeInternalMessageLookup(Function lookupFunction) {
   if (messageLookup is UninitializedLocaleData) {
     messageLookup = lookupFunction();
   }
-}
+}