Remove Compiler access from ResolutionEnqueuer

pkg/compiler/lib/src/types/types.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library types;
 
 import '../common/tasks.dart' show CompilerTask;
 import '../compiler.dart' show Compiler;
 import '../elements/elements.dart';
 import '../inferrer/type_graph_inferrer.dart' show TypeGraphInferrer;
@@ skipping 110 matching lines @@
   TypeMask typeOfIteratorCurrent(ForIn node, elements) =>
       elements.getCurrentTypeMask(node);
 }
 
 /// Global analysis that infers concrete types.
 class GlobalTypeInferenceTask extends CompilerTask {
   // TODO(sigmund): rename at the same time as our benchmarking tools.
   final String name = 'Type inference';
 
   final Compiler compiler;
-  TypesInferrer typesInferrer;
-  CommonMasks masks;
+
+  /// The [TypeInferrer] used by the global type inference. This should by
+  /// accessed from outside this class for testing only.
+  TypesInferrer typesInferrerInternal;
+
   GlobalTypeInferenceResults results;
 
   GlobalTypeInferenceTask(Compiler compiler)
-      : masks = new CommonMasks(compiler),
-        compiler = compiler,
-        super(compiler.measurer) {
-    typesInferrer = new TypeGraphInferrer(compiler, masks);
-  }
+      : compiler = compiler,
+        super(compiler.measurer);
 
   /// Runs the global type-inference algorithm once.
   void runGlobalTypeInference(Element mainElement) {
     measure(() {
-      typesInferrer.analyzeMain(mainElement);
-      typesInferrer.clear();
-      results = new GlobalTypeInferenceResults(typesInferrer, compiler, masks);
+      CommonMasks masks = compiler.closedWorld.commonMasks;
+      typesInferrerInternal ??= new TypeGraphInferrer(compiler, masks);
+      typesInferrerInternal.analyzeMain(mainElement);
+      typesInferrerInternal.clear();
+      results = new GlobalTypeInferenceResults(
+          typesInferrerInternal, compiler, masks);
     });
   }
 }