Make List.shuffle take an optional Random object to use.

pkg/unmodifiable_collection/lib/unmodifiable_collection.dart

Index: pkg/unmodifiable_collection/lib/unmodifiable_collection.dart
diff --git a/pkg/unmodifiable_collection/lib/unmodifiable_collection.dart b/pkg/unmodifiable_collection/lib/unmodifiable_collection.dart
index 2388ccb845ed3f02006de71a02bba908fb012088..ec8dbf01f9085463f2748ec0c4031ce8b2e3ca26 100644
--- a/pkg/unmodifiable_collection/lib/unmodifiable_collection.dart
+++ b/pkg/unmodifiable_collection/lib/unmodifiable_collection.dart
@@ -13,6 +13,7 @@
  */
 library unmodifiable_collection;
 
+import "dart:math" show Random;
 export "dart:collection" show UnmodifiableListView;
 
 /**
@@ -58,7 +59,7 @@ class NonGrowableListView<E> extends _IterableView<E>
 
   void sort([int compare(E a, E b)]) { _source.sort(compare); }
 
-  void shuffle() { _source.shuffle(); }
+  void shuffle([Random random]) { _source.shuffle(random); }
 
   void setRange(int start, int end, Iterable<E> iterable, [int skipCount = 0]) {
     _source.setRange(start, end, iterable, skipCount);