Refactor ConstantSystem

pkg/compiler/lib/src/common/backend_api.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.backend_api;
 
 import 'dart:async' show Future;
 
 import '../common.dart';
 import '../common/codegen.dart' show CodegenImpact;
@@ skipping 191 matching lines @@
 
   /// Returns `true` if [cls] is an intercepted class.
   // TODO(johnniwinther): Rename this to `isInterceptedClass`.
   bool isInterceptorClass(ClassEntity cls);
 
   /// Returns `true` if [cls] is a native class.
   bool isNativeClass(ClassEntity element);
 
   /// Returns `true` if [element] is a native member of a native class.
   bool isNativeMember(MemberEntity element);
+
+  /// Returns the type of the constant map implementation for a const map
+  /// literal of [sourceType]. If [hasProtoKey] the map contains key of value
+  /// '__proto__' and if [onlyStringKeys] all keys are string constants.
+  InterfaceType getConstantMapTypeFor(InterfaceType sourceType,
+      {bool hasProtoKey: false, bool onlyStringKeys: false});
+
+  /// Returns the type of the constant symbol implementation class.
+  InterfaceType get symbolType;
+
+  /// Returns the field of the constant symbol implementation class that holds
+  /// its internal name.
+  FieldEntity get symbolField;
 }