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pkg/dev_compiler/tool/input_sdk/patch/collection_patch.dart

Index: pkg/dev_compiler/tool/input_sdk/patch/collection_patch.dart
diff --git a/pkg/dev_compiler/tool/input_sdk/patch/collection_patch.dart b/pkg/dev_compiler/tool/input_sdk/patch/collection_patch.dart
index 7fccdc3c5994912e9365c6d488cfa9db4d8b1625..5e2a79c9ff31284421a03ad26738a8736721c5a9 100644
--- a/pkg/dev_compiler/tool/input_sdk/patch/collection_patch.dart
+++ b/pkg/dev_compiler/tool/input_sdk/patch/collection_patch.dart
@@ -431,7 +431,7 @@ class _CustomHashMap<K, V> extends _HashMap<K, V> {
   String toString() => Maps.mapToString(this);
 }
 
-class _HashMapKeyIterable<E> extends Iterable<E> implements EfficientLength {
+class _HashMapKeyIterable<E> extends EfficientLengthIterable<E> {
   final _HashMap/*<E, dynamic>*/ _map;
   _HashMapKeyIterable(this._map);
 
@@ -639,8 +639,7 @@ class _Es6LinkedIdentityHashMap<K, V>
   String toString() => Maps.mapToString(this);
 }
 
-class _Es6MapIterable<E> extends Iterable<E>
-                         implements EfficientLength {
+class _Es6MapIterable<E> extends EfficientLengthIterable<E> {
   final _map;
   final bool _isKeys;