Merge WorldImpl with ResolutionWorldBuilderImpl

pkg/compiler/lib/src/enqueue.dart

Index: pkg/compiler/lib/src/enqueue.dart
diff --git a/pkg/compiler/lib/src/enqueue.dart b/pkg/compiler/lib/src/enqueue.dart
index b93812a9baaeeedb7ccb8b937fc375f27c96024f..438db63732577f66931ff9992f791f1c16d80153 100644
--- a/pkg/compiler/lib/src/enqueue.dart
+++ b/pkg/compiler/lib/src/enqueue.dart
@@ -70,6 +70,7 @@ class EnqueueTask extends CompilerTask {
 }
 
 abstract class Enqueuer {
+  // TODO(johnniwinther): Rename to `worldBuilder`.
   WorldBuilder get universe;
   native.NativeEnqueuer get nativeEnqueuer;
   void forgetEntity(Entity entity, Compiler compiler);
@@ -170,8 +171,6 @@ class ResolutionEnqueuer extends EnqueuerImpl {
 
   ResolutionWorldBuilder get universe => _universe;
 
-  OpenWorld get _openWorld => universe.openWorld;
-
   bool get queueIsEmpty => _queue.isEmpty;
 
   DiagnosticReporter get _reporter => _resolution.reporter;
@@ -300,7 +299,7 @@ class ResolutionEnqueuer extends EnqueuerImpl {
         break;
       case TypeUseKind.TYPE_LITERAL:
         if (type.isTypedef) {
-          universe.openWorld.registerTypedef(type.element);
+          universe.registerTypedef(type.element);
         }
         break;
     }
@@ -386,7 +385,7 @@ class ResolutionEnqueuer extends EnqueuerImpl {
     }
 
     applyImpact(backend.registerUsedElement(element, forResolution: true));
-    _openWorld.registerUsedElement(element);
+    _universe.registerUsedElement(element);
 
     ResolutionWorkItem workItem = _resolution.createWorkItem(element);
     _queue.add(workItem);