All strong mode cleaning of dart2js.

pkg/compiler/lib/src/constants/values.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.constants.values;
 
 import '../common.dart';
 import '../common_elements.dart';
 import '../elements/entities.dart';
 import '../elements/types.dart';
@@ skipping 12 matching lines @@
   TYPE,
   INTERCEPTOR,
   SYNTHETIC,
   DEFERRED,
   NON_CONSTANT,
 }
 
 abstract class ConstantValueVisitor<R, A> {
   const ConstantValueVisitor();
 
-  R visitFunction(FunctionConstantValue constant, A arg);
-  R visitNull(NullConstantValue constant, A arg);
-  R visitInt(IntConstantValue constant, A arg);
-  R visitDouble(DoubleConstantValue constant, A arg);
-  R visitBool(BoolConstantValue constant, A arg);
-  R visitString(StringConstantValue constant, A arg);
-  R visitList(ListConstantValue constant, A arg);
-  R visitMap(MapConstantValue constant, A arg);
-  R visitConstructed(ConstructedConstantValue constant, A arg);
-  R visitType(TypeConstantValue constant, A arg);
-  R visitInterceptor(InterceptorConstantValue constant, A arg);
-  R visitSynthetic(SyntheticConstantValue constant, A arg);
-  R visitDeferred(DeferredConstantValue constant, A arg);
-  R visitNonConstant(NonConstantValue constant, A arg);
+  R visitFunction(covariant FunctionConstantValue constant, covariant A arg);
+  R visitNull(covariant NullConstantValue constant, covariant A arg);
+  R visitInt(covariant IntConstantValue constant, covariant A arg);
+  R visitDouble(covariant DoubleConstantValue constant, covariant A arg);
+  R visitBool(covariant BoolConstantValue constant, covariant A arg);
+  R visitString(covariant StringConstantValue constant, covariant A arg);
+  R visitList(covariant ListConstantValue constant, covariant A arg);
+  R visitMap(covariant MapConstantValue constant, covariant A arg);
+  R visitConstructed(
+      covariant ConstructedConstantValue constant, covariant A arg);
+  R visitType(covariant TypeConstantValue constant, covariant A arg);
+  R visitInterceptor(
+      covariant InterceptorConstantValue constant, covariant A arg);
+  R visitSynthetic(covariant SyntheticConstantValue constant, covariant A arg);
+  R visitDeferred(covariant DeferredConstantValue constant, covariant A arg);
+  R visitNonConstant(covariant NonConstantValue constant, covariant A arg);
 }
 
 abstract class ConstantValue {
   const ConstantValue();
 
   /// `true` if this is a valid constant value.
   bool get isConstant => true;
 
   bool get isNull => false;
   bool get isBool => false;
@@ skipping 737 matching lines @@
   DartType getType(CommonElements types) => types.dynamicType;
 
   ConstantValueKind get kind => ConstantValueKind.NON_CONSTANT;
 
   @override
   String toStructuredText() => 'NonConstant';
 
   @override
   String toDartText() => '>>non-constant<<';
 }