Unify symbols sharing across native scripts and runtime.

src/string-iterator.js

Index: src/string-iterator.js
diff --git a/src/string-iterator.js b/src/string-iterator.js
index bb392ef10efbaa908e89d466faadfbcd4b68d14b..4e51a12a2eda14e26fda37469d6e9516a95cf0a3 100644
--- a/src/string-iterator.js
+++ b/src/string-iterator.js
@@ -11,9 +11,12 @@
 // -------------------------------------------------------------------
 // Imports
 
-var GlobalString = global.String;
-
 var ArrayIteratorCreateResultObject;
+var GlobalString = global.String;
+var stringIteratorIteratedStringSymbol =
+    utils.GetPrivateSymbol("string_iterator_iterated_string_symbol");
+var stringIteratorNextIndexSymbol =
+    utils.GetPrivateSymbol("string_iterator_next_index_symbol");
 
 utils.Import(function(from) {
   ArrayIteratorCreateResultObject = from.ArrayIteratorCreateResultObject;
@@ -21,11 +24,6 @@ utils.Import(function(from) {
 
 // -------------------------------------------------------------------
 
-var stringIteratorIteratedStringSymbol =
-    GLOBAL_PRIVATE("StringIterator#iteratedString");
-var stringIteratorNextIndexSymbol = GLOBAL_PRIVATE("StringIterator#next");
-
-
 function StringIterator() {}