Convert GeneratedContent to async and use AnalysisDriver for tasks graph.

pkg/analysis_server/tool/spec/codegen_java.dart

 // Copyright (c) 2014, 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.
 
 /**
  * Tools for Java code generation.
  */
 import 'package:analyzer/src/codegen/tools.dart';
 import 'package:front_end/src/codegen/tools.dart';
 import 'package:html/dom.dart' as dom;
 
 import 'api.dart';
 import 'from_html.dart';
 import 'to_html.dart';
 
 /**
  * Create a [GeneratedFile] that creates Java code and outputs it to [path].
  * [path] uses Posix-style path separators regardless of the OS.
  */
 GeneratedFile javaGeneratedFile(
     String path, CodegenJavaVisitor createVisitor(Api api)) {
-  return new GeneratedFile(path, (String pkgPath) {
+  return new GeneratedFile(path, (String pkgPath) async {
     CodegenJavaVisitor visitor = createVisitor(readApi(pkgPath));
     return visitor.collectCode(visitor.visitApi);
   });
 }
 
 /**
  * Iterate through the values in [map] in the order of increasing keys.
  */
 Iterable<String> _valuesSortedByKey(Map<String, String> map) {
   List<String> keys = map.keys.toList();
@@ skipping 259 matching lines @@
   /**
    * Temporary storage for private fields.
    */
   Map<String, String> privateFields = <String, String>{};
 
   /**
    * Temporary storage for constructors.
    */
   Map<String, String> constructors = <String, String>{};
 }