Add TypeUse.

pkg/compiler/lib/src/resolution/resolution.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 dart2js.resolution;
 
 import 'dart:collection' show Queue;
 
 import '../common.dart';
 import '../common/names.dart' show
@@ skipping 31 matching lines @@
 import '../tokens/token.dart' show
     isBinaryOperator,
     isMinusOperator,
     isTernaryOperator,
     isUnaryOperator,
     isUserDefinableOperator;
 import '../tree/tree.dart';
 import '../universe/call_structure.dart' show
     CallStructure;
 import '../universe/use.dart' show
-    StaticUse;
+    StaticUse,
+    TypeUse;
 import '../universe/world_impact.dart' show
     WorldImpact;
 import '../util/util.dart' show
     Link,
     LinkBuilder,
     Setlet;
 
 import 'class_hierarchy.dart';
 import 'class_members.dart' show MembersCreator;
 import 'constructors.dart';
@@ skipping 307 matching lines @@
       // TODO(johnniwinther): Avoid analyzing initializers if
       // [Compiler.analyzeSignaturesOnly] is set.
       visitor.visit(initializer);
     } else if (modifiers.isConst) {
       reporter.reportErrorMessage(
           element, MessageKind.CONST_WITHOUT_INITIALIZER);
     } else if (modifiers.isFinal && !element.isInstanceMember) {
       reporter.reportErrorMessage(
           element, MessageKind.FINAL_WITHOUT_INITIALIZER);
     } else {
-      registry.registerInstantiatedType(coreTypes.nullType);
+      // TODO(johnniwinther): Register a feature instead.
+      registry.registerTypeUse(new TypeUse.instantiation(coreTypes.nullType));
     }
 
     if (Elements.isStaticOrTopLevelField(element)) {
       visitor.addDeferredAction(element, () {
         if (element.modifiers.isConst) {
           element.constant = constantCompiler.compileConstant(element);
         } else {
           constantCompiler.compileVariable(element);
         }
       });
@@ skipping 698 matching lines @@
   TreeElements get treeElements {
     assert(invariant(this, _treeElements !=null,
         message: "TreeElements have not been computed for $this."));
     return _treeElements;
   }
 
   void reuseElement() {
     _treeElements = null;
   }
 }