Use entity WorldImpl where possible

pkg/compiler/lib/src/universe/class_set.dart

Index: pkg/compiler/lib/src/universe/class_set.dart
diff --git a/pkg/compiler/lib/src/universe/class_set.dart b/pkg/compiler/lib/src/universe/class_set.dart
index dd7f0636901c51b4c12300e95600044fe7bc9634..3eaf8cbe0af8f0420e320a777876f78110b583dc 100644
--- a/pkg/compiler/lib/src/universe/class_set.dart
+++ b/pkg/compiler/lib/src/universe/class_set.dart
@@ -19,7 +19,7 @@ enum Instantiation {
   ABSTRACTLY_INSTANTIATED,
 }
 
-/// Node for [cls] in a tree forming the subclass relation of [ClassElement]s.
+/// Node for [cls] in a tree forming the subclass relation of [ClassEntity]s.
 ///
 /// This is used by the [ClosedWorld] to perform queries on subclass and subtype
 /// relations.
@@ -101,7 +101,7 @@ class ClassHierarchyNode {
 
   final int hierarchyDepth;
 
-  ClassElement _leastUpperInstantiatedSubclass;
+  ClassEntity _leastUpperInstantiatedSubclass;
   int _instantiatedSubclassCount = 0;
 
   /// `true` if [cls] has been directly instantiated.
@@ -237,7 +237,7 @@ class ClassHierarchyNode {
   /// Subclasses are included if their instantiation properties intersect with
   /// their corresponding [Instantiation] values in [mask]. If [strict] is
   /// `true`, [cls] itself is _not_ returned.
-  Iterable<ClassElement> subclassesByMask(EnumSet<Instantiation> mask,
+  Iterable<ClassEntity> subclassesByMask(EnumSet<Instantiation> mask,
       {bool strict: false}) {
     return new ClassHierarchyNodeIterable(this, mask, includeRoot: !strict);
   }
@@ -249,10 +249,9 @@ class ClassHierarchyNode {
   /// [predicate] is applied to subclasses if their instantiation properties
   /// intersect with their corresponding [Instantiation] values in [mask]. If
   /// [strict] is `true`, [predicate] is _not_ called on [cls] itself.
-  bool anySubclass(
-      bool predicate(ClassElement cls), EnumSet<Instantiation> mask,
+  bool anySubclass(bool predicate(ClassEntity cls), EnumSet<Instantiation> mask,
       {bool strict: false}) {
-    IterationStep wrapper(ClassElement cls) {
+    IterationStep wrapper(ClassEntity cls) {
       return predicate(cls) ? IterationStep.STOP : IterationStep.CONTINUE;
     }
 
@@ -301,7 +300,7 @@ class ClassHierarchyNode {
   /// Returns the most specific subclass of [cls] (including [cls]) that is
   /// directly instantiated or a superclass of all directly instantiated
   /// subclasses. If [cls] is not instantiated, `null` is returned.
-  ClassElement getLubOfInstantiatedSubclasses() {
+  ClassEntity getLubOfInstantiatedSubclasses() {
     if (!isInstantiated) return null;
     if (_leastUpperInstantiatedSubclass == null) {
       _leastUpperInstantiatedSubclass =
@@ -310,7 +309,7 @@ class ClassHierarchyNode {
     return _leastUpperInstantiatedSubclass;
   }
 
-  ClassElement _computeLeastUpperInstantiatedSubclass() {
+  ClassEntity _computeLeastUpperInstantiatedSubclass() {
     if (isExplicitlyInstantiated) {
       return cls;
     }
@@ -412,7 +411,7 @@ class ClassHierarchyNode {
 }
 
 /// Object holding the subclass and subtype relation for a single
-/// [ClassElement].
+/// [ClassEntity].
 ///
 /// The subclass relation for a class `C` is modelled through a reference to
 /// the [ClassHierarchyNode] for `C` in the global [ClassHierarchyNode] tree
@@ -457,7 +456,7 @@ class ClassHierarchyNode {
 ///
 class ClassSet {
   final ClassHierarchyNode node;
-  ClassElement _leastUpperInstantiatedSubtype;
+  ClassEntity _leastUpperInstantiatedSubtype;
 
   /// A list of the class hierarchy nodes for the subtypes that declare a
   /// subtype relationship to [cls] either directly or indirectly.
@@ -479,7 +478,7 @@ class ClassSet {
 
   ClassSet(this.node);
 
-  ClassElement get cls => node.cls;
+  ClassEntity get cls => node.cls;
 
   /// Returns the number of directly instantiated subtypes of [cls].
   int get instantiatedSubtypeCount {
@@ -517,7 +516,7 @@ class ClassSet {
   /// Subclasses are included if their instantiation properties intersect with
   /// their corresponding [Instantiation] values in [mask]. If [strict] is
   /// `true`, [cls] itself is _not_ returned.
-  Iterable<ClassElement> subclassesByMask(EnumSet<Instantiation> mask,
+  Iterable<ClassEntity> subclassesByMask(EnumSet<Instantiation> mask,
       {bool strict: false}) {
     return node.subclassesByMask(mask, strict: strict);
   }
@@ -528,7 +527,7 @@ class ClassSet {
   /// subtypes of [cls] are returned if [includeDirectlyInstantiated],
   /// [includeIndirectlyInstantiated], and [includeUninstantiated] are `true`,
   /// respectively. If [strict] is `true`, [cls] itself is _not_ returned.
-  Iterable<ClassElement> subtypes(
+  Iterable<ClassEntity> subtypes(
       {bool includeDirectlyInstantiated: true,
       bool includeIndirectlyInstantiated: true,
       bool includeUninstantiated: true,
@@ -545,7 +544,7 @@ class ClassSet {
   /// Subtypes are included if their instantiation properties intersect with
   /// their corresponding [Instantiation] values in [mask]. If [strict] is
   /// `true`, [cls] itself is _not_ returned.
-  Iterable<ClassElement> subtypesByMask(EnumSet<Instantiation> mask,
+  Iterable<ClassEntity> subtypesByMask(EnumSet<Instantiation> mask,
       {bool strict: false}) {
     if (_subtypes == null) {
       return node.subclassesByMask(mask, strict: strict);
@@ -562,8 +561,7 @@ class ClassSet {
   /// [predicate] is applied to subclasses if their instantiation properties
   /// intersect with their corresponding [Instantiation] values in [mask]. If
   /// [strict] is `true`, [predicate] is _not_ called on [cls] itself.
-  bool anySubclass(
-      bool predicate(ClassElement cls), EnumSet<Instantiation> mask,
+  bool anySubclass(bool predicate(ClassEntity cls), EnumSet<Instantiation> mask,
       {bool strict: false}) {
     return node.anySubclass(predicate, mask, strict: strict);
   }
@@ -594,9 +592,9 @@ class ClassSet {
   /// [predicate] is applied to subtypes if their instantiation properties
   /// intersect with their corresponding [Instantiation] values in [mask]. If
   /// [strict] is `true`, [predicate] is _not_ called on [cls] itself.
-  bool anySubtype(bool predicate(ClassElement cls), EnumSet<Instantiation> mask,
+  bool anySubtype(bool predicate(ClassEntity cls), EnumSet<Instantiation> mask,
       {bool strict: false}) {
-    IterationStep wrapper(ClassElement cls) {
+    IterationStep wrapper(ClassEntity cls) {
       return predicate(cls) ? IterationStep.STOP : IterationStep.CONTINUE;
     }
 
@@ -686,14 +684,14 @@ class ClassSet {
   /// Returns the most specific subtype of [cls] (including [cls]) that is
   /// directly instantiated or a superclass of all directly instantiated
   /// subtypes. If no subtypes of [cls] are instantiated, `null` is returned.
-  ClassElement getLubOfInstantiatedSubtypes() {
+  ClassEntity getLubOfInstantiatedSubtypes() {
     if (_leastUpperInstantiatedSubtype == null) {
       _leastUpperInstantiatedSubtype = _computeLeastUpperInstantiatedSubtype();
     }
     return _leastUpperInstantiatedSubtype;
   }
 
-  ClassElement _computeLeastUpperInstantiatedSubtype() {
+  ClassEntity _computeLeastUpperInstantiatedSubtype() {
     if (node.isExplicitlyInstantiated) {
       return cls;
     }
@@ -736,7 +734,7 @@ class ClassSet {
 }
 
 /// Iterable for subclasses of a [ClassHierarchyNode].
-class ClassHierarchyNodeIterable extends IterableBase<ClassElement> {
+class ClassHierarchyNodeIterable extends IterableBase<ClassEntity> {
   final ClassHierarchyNode root;
   final EnumSet<Instantiation> mask;
   final bool includeRoot;
@@ -746,7 +744,7 @@ class ClassHierarchyNodeIterable extends IterableBase<ClassElement> {
   }
 
   @override
-  Iterator<ClassElement> get iterator {
+  Iterator<ClassEntity> get iterator {
     return new ClassHierarchyNodeIterator(this);
   }
 }
@@ -754,7 +752,7 @@ class ClassHierarchyNodeIterable extends IterableBase<ClassElement> {
 /// Iterator for subclasses of a [ClassHierarchyNode].
 ///
 /// Classes are returned in pre-order DFS fashion.
-class ClassHierarchyNodeIterator implements Iterator<ClassElement> {
+class ClassHierarchyNodeIterator implements Iterator<ClassEntity> {
   final ClassHierarchyNodeIterable iterable;
 
   /// The class node holding the [current] class.
@@ -781,7 +779,7 @@ class ClassHierarchyNodeIterator implements Iterator<ClassElement> {
   }
 
   @override
-  ClassElement get current {
+  ClassEntity get current {
     return currentNode != null ? currentNode.cls : null;
   }
 
@@ -833,7 +831,7 @@ class ClassHierarchyNodeIterator implements Iterator<ClassElement> {
 }
 
 /// Iterable for the subtypes in a [ClassSet].
-class SubtypesIterable extends IterableBase<ClassElement> {
+class SubtypesIterable extends IterableBase<ClassEntity> {
   final ClassSet subtypeSet;
   final EnumSet<Instantiation> mask;
   final bool includeRoot;
@@ -842,13 +840,13 @@ class SubtypesIterable extends IterableBase<ClassElement> {
       {this.includeRoot: true});
 
   @override
-  Iterator<ClassElement> get iterator => new SubtypesIterator(this);
+  Iterator<ClassEntity> get iterator => new SubtypesIterator(this);
 }
 
 /// Iterator for the subtypes in a [ClassSet].
-class SubtypesIterator extends Iterator<ClassElement> {
+class SubtypesIterator extends Iterator<ClassEntity> {
   final SubtypesIterable iterable;
-  Iterator<ClassElement> elements;
+  Iterator<ClassEntity> elements;
   Iterator<ClassHierarchyNode> hierarchyNodes;
 
   SubtypesIterator(this.iterable);
@@ -858,7 +856,7 @@ class SubtypesIterator extends Iterator<ClassElement> {
   EnumSet<Instantiation> get mask => iterable.mask;
 
   @override
-  ClassElement get current {
+  ClassEntity get current {
     if (elements != null) {
       return elements.current;
     }
@@ -907,4 +905,4 @@ enum IterationStep {
 /// Visiting function used for the `forEachX` functions of [ClassHierarchyNode]
 /// and [ClassSet]. The return value controls the continued iteration. If `null`
 /// is returned, iteration continues to the end.
-typedef IterationStep ForEachFunction(ClassElement cls);
+typedef IterationStep ForEachFunction(ClassEntity cls);