Revert r27992: some browser tests fail.

sdk/lib/_internal/compiler/implementation/inferrer/type_graph_nodes.dart

Index: sdk/lib/_internal/compiler/implementation/inferrer/type_graph_nodes.dart
===================================================================
--- sdk/lib/_internal/compiler/implementation/inferrer/type_graph_nodes.dart	(revision 27994)
+++ sdk/lib/_internal/compiler/implementation/inferrer/type_graph_nodes.dart	(working copy)
@@ -92,17 +92,6 @@
     assignments = const <TypeInformation>[];
     users = const <TypeInformation>[];
   }
-
-  bool reachedBy(TypeInformation info, TypeGraphInferrerEngine inferrer) {
-    return true;
-  }
-
-  accept(TypeInformationVisitor visitor);
-
-  /// The [Element] where this [TypeInformation] was created. May be
-  /// for some [TypeInformation] nodes, where we do not need to store
-  /// the information.
-  Element get owner => null;
 }
 
 /**
@@ -279,12 +268,6 @@
   }
 
   String toString() => 'Element $element $type';
-
-  accept(TypeInformationVisitor visitor) {
-    return visitor.visitElementTypeInformation(this);
-  }
-
-  Element get owner => element.getOutermostEnclosingMemberOrTopLevel();
 }
 
 /**
@@ -318,8 +301,6 @@
 
   /// Return an iterable over the targets of this call.
   Iterable<Element> get callees;
-
-  Element get owner => caller;
 }
 
 class StaticCallSiteTypeInformation extends CallSiteTypeInformation {
@@ -363,14 +344,6 @@
   }
 
   Iterable<Element> get callees => [calledElement.implementation];
-
-  bool reachedBy(TypeInformation info, TypeGraphInferrerEngine inferrer) {
-    return info == inferrer.types.getInferredTypeOf(calledElement);
-  }
-
-  accept(TypeInformationVisitor visitor) {
-    return visitor.visitStaticCallSiteTypeInformation(this);
-  }
 }
 
 class DynamicCallSiteTypeInformation extends CallSiteTypeInformation {
@@ -533,17 +506,7 @@
     super.giveUp(inferrer);
   }
 
-  bool reachedBy(TypeInformation info, TypeGraphInferrerEngine inferrer) {
-    return targets
-            .map((element) => inferrer.types.getInferredTypeOf(element))
-            .any((other) => other == info);
-  }
-
-  String toString() => 'Call site $call on ${receiver.type} $type';
-
-  accept(TypeInformationVisitor visitor) {
-    return visitor.visitDynamicCallSiteTypeInformation(this);
-  }
+  String toString() => 'Call site $call ${receiver.type} $type';
 }
 
 class ClosureCallSiteTypeInformation extends CallSiteTypeInformation {
@@ -566,14 +529,10 @@
   }
 
   Iterable<Element> get callees {
-    throw new UnsupportedError("Cannot compute callees of a closure call.");
+    throw new UnsupportedError("Cannot compute callees of a closure.");
   }
 
   String toString() => 'Closure call $call on $closure';
-
-  accept(TypeInformationVisitor visitor) {
-    return visitor.visitClosureCallSiteTypeInformation(this);
-  }
 }
 
 /**
@@ -610,10 +569,6 @@
   }
 
   String toString() => 'Type $type';
-
-  accept(TypeInformationVisitor visitor) {
-    return visitor.visitConcreteTypeInformation(this);
-  }
 }
 
 /**
@@ -647,28 +602,23 @@
   }
 
   String toString() => 'Narrow ${assignments.first} to $typeAnnotation $type';
-
-  accept(TypeInformationVisitor visitor) {
-    return visitor.visitNarrowTypeInformation(this);
-  }
 }
 
 /**
- * A [ContainerTypeInformation] is a [TypeInformation] created
+ * A [ContainerTypeInformation] is a [ConcreteTypeInformation] created
  * for each `List` instantiations.
  */
-class ContainerTypeInformation extends TypeInformation {
-  final ElementInContainerTypeInformation elementType;
+class ContainerTypeInformation extends ConcreteTypeInformation {
+  final TypeInformation elementType;
 
-  ContainerTypeInformation(containerType, this.elementType) {
-    type = containerType;
+  ContainerTypeInformation(containerType, this.elementType)
+      : super(containerType);
+
+  void addUser(TypeInformation user) {
+    elementType.addUser(user);
   }
 
   String toString() => 'Container type $type';
-
-  accept(TypeInformationVisitor visitor) {
-    return visitor.visitContainerTypeInformation(this);
-  }
 }
 
 /**
@@ -679,27 +629,17 @@
   final ContainerTypeMask container;
 
   ElementInContainerTypeInformation(elementType, this.container) {
+    // [elementType] is not null for const lists.
     if (elementType != null) addAssignment(elementType);
   }
 
-  bool get isInConstContainer {
-    LiteralList literal = container.allocationNode.asLiteralList();
-    return (literal != null) && literal.isConst();
-  }
-
   TypeMask refine(TypeGraphInferrerEngine inferrer) {
-    if (!isInConstContainer) {
-      return inferrer.types.dynamicType.type;
-    }
+    if (assignments.isEmpty) return inferrer.types.dynamicType.type;
     return container.elementType =
         inferrer.types.computeTypeMask(assignments);
   }
 
   String toString() => 'Element in container $type';
-
-  accept(TypeInformationVisitor visitor) {
-    return visitor.visitElementInContainerTypeInformation(this);
-  }
 }
 
 /**
@@ -718,21 +658,4 @@
   }
 
   String toString() => 'Phi $element $type';
-
-  accept(TypeInformationVisitor visitor) {
-    return visitor.visitPhiElementTypeInformation(this);
-  }
 }
-
-abstract class TypeInformationVisitor<T> {
-  T visitNarrowTypeInformation(NarrowTypeInformation info);
-  T visitPhiElementTypeInformation(PhiElementTypeInformation info);
-  T visitElementInContainerTypeInformation(
-      ElementInContainerTypeInformation info);
-  T visitContainerTypeInformation(ContainerTypeInformation info);
-  T visitConcreteTypeInformation(ConcreteTypeInformation info);
-  T visitClosureCallSiteTypeInformation(ClosureCallSiteTypeInformation info);
-  T visitStaticCallSiteTypeInformation(StaticCallSiteTypeInformation info);
-  T visitDynamicCallSiteTypeInformation(DynamicCallSiteTypeInformation info);
-  T visitElementTypeInformation(ElementTypeInformation info);
-}