Remove requiredTypes

pkg/compiler/lib/src/resolution/tree_elements.dart

Index: pkg/compiler/lib/src/resolution/tree_elements.dart
diff --git a/pkg/compiler/lib/src/resolution/tree_elements.dart b/pkg/compiler/lib/src/resolution/tree_elements.dart
index 8d3071c8f4522a1092383661c79f3b6751f09ed6..ae0b67f4037bcc59bcf276c7b8a31d8e6a3d8328 100644
--- a/pkg/compiler/lib/src/resolution/tree_elements.dart
+++ b/pkg/compiler/lib/src/resolution/tree_elements.dart
@@ -24,11 +24,6 @@ abstract class TreeElements {
   AnalyzableElement get analyzedElement;
   Iterable<Node> get superUses;
 
-  /// The set of types that this TreeElement depends on.
-  /// This includes instantiated types, types in is-checks and as-expressions
-  /// and in checked mode the types of all type-annotations.
-  Iterable<DartType> get requiredTypes;
-
   void forEachConstantNode(f(Node n, ConstantExpression c));
 
   Element operator[](Node node);
@@ -80,9 +75,6 @@ abstract class TreeElements {
   /// Returns the type that the type literal [node] refers to.
   DartType getTypeLiteralType(Send node);
 
-  /// Register a dependency on [type].
-  void addRequiredType(DartType type);
-
   /// Returns a list of nodes that potentially mutate [element] anywhere in its
   /// scope.
   List<Node> getPotentialMutations(VariableElement element);
@@ -125,7 +117,6 @@ class TreeElementMapping extends TreeElements {
   Map<VariableElement, List<Node>> _potentiallyMutatedInClosure;
   Map<Node, Map<VariableElement, List<Node>>> _accessedByClosureIn;
   Maplet<Send, SendStructure> _sendStructureMap;
-  Setlet<DartType> _requiredTypes;
   bool containsTryStatement = false;
 
   /// Map from nodes to the targets they define.
@@ -186,19 +177,6 @@ class TreeElementMapping extends TreeElements {
 
   DartType getType(Node node) => _types != null ? _types[node] : null;
 
-  void addRequiredType(DartType type) {
-    if (_requiredTypes == null) _requiredTypes = new Setlet<DartType>();
-    _requiredTypes.add(type);
-  }
-
-  Iterable<DartType> get requiredTypes {
-    if (_requiredTypes == null) {
-      return const <DartType>[];
-    } else {
-      return _requiredTypes;
-    }
-  }
-
   Iterable<Node> get superUses {
     return _superUses != null ? _superUses : const <Node>[];
   }