Don't require Transformer methods to return Futures.

pkg/barback/test/transformer/declaring_bad.dart

 // Copyright (c) 2013, 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 barback.test.transformer.declaring_bad;
 
-import 'dart:async';
-
 import 'package:barback/barback.dart';
-import 'package:barback/src/utils.dart';
 
 import 'bad.dart';
 import 'mock.dart';
 
 /// A transformer that throws an exception when run, after generating the
 /// given outputs.
 class DeclaringBadTransformer extends MockTransformer
     implements DeclaringTransformer {
   /// Whether this should throw an error in [declareOutputs].
   final bool declareError;
 
   /// Whether this should throw an error in [apply].
   final bool applyError;
 
   /// The id of the output asset to emit.
   final AssetId output;
 
   DeclaringBadTransformer(String output, {bool declareError: true,
           bool applyError: false})
       : this.output = new AssetId.parse(output),
         this.declareError = declareError,
         this.applyError = applyError;
 
-  Future<bool> doIsPrimary(AssetId id) => new Future.value(true);
+  bool doIsPrimary(AssetId id) => true;
 
-  Future doApply(Transform transform) {
-    return newFuture(() {
-      transform.addOutput(new Asset.fromString(output, "bad out"));
-      if (applyError) throw BadTransformer.ERROR;
-    });
+  void doApply(Transform transform) {
+    transform.addOutput(new Asset.fromString(output, "bad out"));
+    if (applyError) throw BadTransformer.ERROR;
   }
 
-  Future declareOutputs(DeclaringTransform transform) {
-    return newFuture(() {
-      if (consumePrimary) transform.consumePrimary();
-      transform.declareOutput(output);
-      if (declareError) throw BadTransformer.ERROR;
-    });
+  void declareOutputs(DeclaringTransform transform) {
+    if (consumePrimary) transform.consumePrimary();
+    transform.declareOutput(output);
+    if (declareError) throw BadTransformer.ERROR;
   }
 }