initial sync*, part of #221

lib/runtime/dart/collection.js

Index: lib/runtime/dart/collection.js
diff --git a/lib/runtime/dart/collection.js b/lib/runtime/dart/collection.js
index b127922a2dcde77248039cb5e212aa40852273c9..2d6a57a71a2af12ab0057e269addf509a0d459c1 100644
--- a/lib/runtime/dart/collection.js
+++ b/lib/runtime/dart/collection.js
@@ -3630,7 +3630,7 @@ dart_library.library('dart/collection', null, /* Imports */[
       containsValue(value) {
         let found = false;
         let initialSplayCount = this[_splayCount];
-        let visit = node => {
+        let visit = (function(node) {
           while (node != null) {
             if (dart.equals(node.value, value))
               return true;
@@ -3642,7 +3642,7 @@ dart_library.library('dart/collection', null, /* Imports */[
             node = dart.as(node.left, _SplayTreeMapNode);
           }
           return false;
-        };
+        }).bind(this);
         dart.fn(visit, core.bool, [_SplayTreeMapNode]);
         return visit(dart.as(this[_root], _SplayTreeMapNode));
       }