Add support for the new function-type syntax.

pkg/compiler/lib/src/tree/unparser.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 import 'package:front_end/src/fasta/scanner.dart' show Token;
 import 'package:front_end/src/fasta/scanner/token_constants.dart' as Tokens
     show IDENTIFIER_TOKEN, KEYWORD_TOKEN, PLUS_TOKEN;
 import '../util/util.dart';
 import 'nodes.dart';
 
@@ skipping 530 matching lines @@
     write(' ');
     visit(node.expression);
   }
 
   visitAwait(Await node) {
     write(node.awaitToken.value);
     write(' ');
     visit(node.expression);
   }
 
-  visitTypeAnnotation(TypeAnnotation node) {
+  visitNominalTypeAnnotation(NominalTypeAnnotation node) {
     visit(node.typeName);
     visit(node.typeArguments);
   }
 
+  visitFunctionTypeAnnotation(FunctionTypeAnnotation node) {
+    visit(node.returnType);
+    write(' Function');
+    visit(node.typeParameters);
+    visit(node.formals);
+  }
+
   visitTypeVariable(TypeVariable node) {
     visit(node.name);
     if (node.bound != null) {
       write(' extends ');
       visit(node.bound);
     }
   }
 
   visitVariableDefinitions(VariableDefinitions node) {
     if (node.metadata != null) {
@@ skipping 198 matching lines @@
     visit(node.block);
   }
 
   visitTypedef(Typedef node) {
     addToken(node.typedefKeyword);
     if (node.returnType != null) {
       visit(node.returnType);
       write(' ');
     }
     visit(node.name);
-    if (node.typeParameters != null) {
-      visit(node.typeParameters);
+    if (node.templateParameters != null) {
+      visit(node.templateParameters);
     }
     visit(node.formals);
     write(node.endToken.value);
   }
 
   visitLibraryName(LibraryName node) {
     addToken(node.libraryKeyword);
     node.visitChildren(this);
     write(node.getEndToken().value);
     newline();
@@ skipping 111 matching lines @@
     throw 'internal error'; // Should not be called.
   }
 
   visitStatement(Statement node) {
     throw 'internal error'; // Should not be called.
   }
 
   visitStringNode(StringNode node) {
     throw 'internal error'; // Should not be called.
   }
+
+  visitTypeAnnotation(TypeAnnotation node) {
+    throw 'internal error'; // Should not be called.
+  }
 }