Rename Universe to WorldBuilder.

pkg/compiler/lib/src/universe/use.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.
 
 /// This library defines individual world impacts.
 ///
 /// We call these building blocks `uses`. Each `use` is a single impact of the
 /// world. Some example uses are:
 ///
 ///  * an invocation of a top level function
 ///  * a call to the `foo()` method on an unknown class.
 ///  * an instantiation of class T
 ///
 /// The different compiler stages combine these uses into `WorldImpact` objects,
 /// which are later used to construct a closed-world understanding of the
 /// program.
 library dart2js.universe.use;
 
 import '../closure.dart' show BoxFieldElement;
 import '../common.dart';
 import '../dart_types.dart';
 import '../elements/elements.dart';
 import '../util/util.dart' show Hashing;
 import '../world.dart' show World;
 import 'call_structure.dart' show CallStructure;
 import 'selector.dart' show Selector;
-import 'universe.dart' show ReceiverConstraint;
+import 'world_builder.dart' show ReceiverConstraint;
 
 enum DynamicUseKind { INVOKE, GET, SET, }
 
 /// The use of a dynamic property. [selector] defined the name and kind of the
 /// property and [mask] defines the known constraint for the object on which
 /// the property is accessed.
 class DynamicUse {
   final Selector selector;
   final ReceiverConstraint mask;
 
@@ skipping 272 matching lines @@
   }
 
   bool operator ==(other) {
     if (identical(this, other)) return true;
     if (other is! TypeUse) return false;
     return type == other.type && kind == other.kind;
   }
 
   String toString() => 'TypeUse($type,$kind)';
 }