Rename buildOutline() and separate 'build' and 'writeProgram()'.

pkg/front_end/lib/src/fasta/dill/dill_target.dart

 // Copyright (c) 2016, 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.
 
 library fasta.dill_target;
 
 import 'dart:async' show Future;
 
 import 'package:kernel/ast.dart' show Class;
 
@@ skipping 16 matching lines @@
 
   void addSourceInformation(
       Uri uri, List<int> lineStarts, List<int> sourceCode) {
     internalError("Unsupported operation.");
   }
 
   void read(Uri uri) {
     internalError("Unsupported operation.");
   }
 
-  Future<Null> writeProgram(Uri uri) {
+  @override
+  Future<Null> buildProgram() {
     return internalError("not implemented.");
   }
 
   @override
-  Future<Null> computeOutline() async {
-    if (loader.libraries.isEmpty) return null;
-    await loader.buildOutlines();
+  Future<Null> buildOutlines() async {
+    if (loader.libraries.isNotEmpty) {
+      await loader.buildOutlines();
+    }
     isLoaded = true;
-    return null;
   }
 
   DillLibraryBuilder createLibraryBuilder(Uri uri, Uri fileUri) {
     return new DillLibraryBuilder(uri, loader);
   }
 
   void addDirectSupertype(ClassBuilder cls, Set<ClassBuilder> set) {}
 
   List<ClassBuilder> collectAllClasses() {
     return null;
   }
 
   void breakCycle(ClassBuilder cls) {}
 
   Class get objectClass => loader.coreLibrary["Object"].target;
 }