Address the remaining review comments on http://chromiumcodereview.appspot.com/9431029.

lib/compiler/implementation/ssa/tracer.dart

Index: lib/compiler/implementation/ssa/tracer.dart
diff --git a/lib/compiler/implementation/ssa/tracer.dart b/lib/compiler/implementation/ssa/tracer.dart
index dc91f69cec9fd54f5bfe0b70c7791790bc0373d6..bd6b4ddd0a6d3eb6d8b293aa79bdd453d0567548 100644
--- a/lib/compiler/implementation/ssa/tracer.dart
+++ b/lib/compiler/implementation/ssa/tracer.dart
@@ -419,7 +419,7 @@ class HInstructionStringifier implements HVisitor<String> {
   }
 
   String visitIs(HIs node) {
-    String type = node.typeName.toString();
+    String type = node.typeExpression.toString();
     return "TypeTest: ${temporaryId(node.expression)} is $type";
   }
 }