Substitution handled for most Send nodes.

lib/compiler/implementation/elements/elements.dart

Index: lib/compiler/implementation/elements/elements.dart
diff --git a/lib/compiler/implementation/elements/elements.dart b/lib/compiler/implementation/elements/elements.dart
index 00ead02f822f0dc39e470fa607a31239f2e76fd2..01dc5707385cb7b796a6e953e8bced1569a4e765 100644
--- a/lib/compiler/implementation/elements/elements.dart
+++ b/lib/compiler/implementation/elements/elements.dart
@@ -813,13 +813,13 @@ class VoidElement extends Element {
 
 class ClassElement extends ContainerElement {
   final int id;
-  Type type;
-  Type supertype;
-  Type defaultClass;
+  InterfaceType type;
+  InterfaceType supertype;
+  InterfaceType defaultClass;
   Link<Element> members = const EmptyLink<Element>();
   Map<SourceString, Element> localMembers;
   Map<SourceString, Element> constructors;
-  Link<Type> interfaces = const EmptyLink<Type>();
+  Link<InterfaceType> interfaces = const EmptyLink<InterfaceType>();
   LinkedHashMap<SourceString, TypeVariableElement> typeParameters;
   bool isResolved = false;
   bool isBeingResolved = false;
@@ -827,7 +827,7 @@ class ClassElement extends ContainerElement {
   // compilation. They don't have any user-side counter-part.
   Link<Element> backendMembers = const EmptyLink<Element>();
 
-  Link<Type> allSupertypes;
+  Link<InterfaceType> allSupertypes;
   ClassElement patch = null;
   Node defaultClause;  // Only for interfaces.
 
@@ -881,7 +881,7 @@ class ClassElement extends ContainerElement {
     }
   }
 
-  Type computeType(compiler) {
+  InterfaceType computeType(compiler) {
     ensureParametersAndType(compiler);
     return type;
   }
@@ -1211,11 +1211,11 @@ class TargetElement extends Element {
 class TypeVariableElement extends Element {
   final Node node;
   Type bound;
-  Type type;
+  TypeVariableType type;
   TypeVariableElement(name, Element enclosing, this.node, this.type,
                       [this.bound])
     : super(name, ElementKind.TYPE_VARIABLE, enclosing);
-  Type computeType(compiler) => type;
+  TypeVariableType computeType(compiler) => type;
   Node parseNode(compiler) => node;
   toString() => "${enclosingElement.toString()}.${name.slowToString()}";
 }