Revert r22847: some dart2dart tests fail.

sdk/lib/_internal/compiler/implementation/dart_types.dart

Index: sdk/lib/_internal/compiler/implementation/dart_types.dart
===================================================================
--- sdk/lib/_internal/compiler/implementation/dart_types.dart	(revision 22847)
+++ sdk/lib/_internal/compiler/implementation/dart_types.dart	(working copy)
@@ -521,9 +521,7 @@
     ClassElement classElement = element;
     InterfaceType receiver = this;
     InterfaceType declarer = receiver;
-    // TODO(johnniwinther): Lookup and callers should handle private members and
-    // injected members.
-    Element member = classElement.implementation.lookupLocalMember(name);
+    Element member = classElement.lookupLocalMember(name);
     if (member != null) {
       return createMember(receiver, declarer, member);
     }
@@ -535,7 +533,7 @@
       if (supertype.element.isMixinApplication) continue;
       declarer = supertype;
       ClassElement lookupTarget = declarer.element;
-      member = lookupTarget.implementation.lookupLocalMember(name);
+      member = lookupTarget.lookupLocalMember(name);
       if (member != null) {
         return createMember(receiver, declarer, member);
       }