Patch refactoring.

lib/compiler/implementation/dart_backend/backend.dart

Index: lib/compiler/implementation/dart_backend/backend.dart
diff --git a/lib/compiler/implementation/dart_backend/backend.dart b/lib/compiler/implementation/dart_backend/backend.dart
index 0f9ec2b54a12308d9798526044d4b42cdb481b2d..7e1a558606f17b2aa5fd80ff0271dd6b43ce834a 100644
--- a/lib/compiler/implementation/dart_backend/backend.dart
+++ b/lib/compiler/implementation/dart_backend/backend.dart
@@ -200,7 +200,8 @@ class DartBackend extends Backend {
     final fixedMemberNames = new Set<String>();
     for (final library in compiler.libraries.getValues()) {
       if (!library.isPlatformLibrary) continue;
-      for (final element in library.localMembers) {
+      // TODO(johnniwinther): Should we include injected members?
+      library.forEachLocalMember((Element element) {
         if (element is ClassElement) {
           ClassElement classElement = element;
           for (final member in classElement.localMembers) {
@@ -215,7 +216,7 @@ class DartBackend extends Backend {
         } else {
           fixedMemberNames.add(element.name.slowToString());
         }
-      }
+      });
     }
     // TODO(antonm): TypeError.srcType and TypeError.dstType are defined in
     // runtime/lib/error.dart. Overall, all DartVM specific libs should be