Revert "Use native async/await support in pub."

sdk/lib/_internal/pub_generated/test/dependency_computer/utils.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS d.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 pub_tests;
 
 import 'package:barback/barback.dart';
 import 'package:path/path.dart' as p;
 import 'package:scheduled_test/scheduled_test.dart';
 
@@ skipping 48 matching lines @@
 }
 
 /// Expects that [DependencyComputer.transformersNeededByLibrary] will return
 /// transformer ids matching [expected] when run on the library identified by
 /// [id].
 void expectLibraryDependencies(String id, Iterable<String> expected) {
   expected = expected.toSet();
 
   schedule(() {
     var computer = new DependencyComputer(_loadPackageGraph());
-    var result = computer.transformersNeededByLibrary(new AssetId.parse(id))
-        .map((id) => id.toString()).toSet();
+    var result = computer.transformersNeededByLibrary(
+        new AssetId.parse(id)).map((id) => id.toString()).toSet();
     expect(result, equals(expected));
   }, "expect dependencies to match $expected");
 }
 
 /// Loads a [PackageGraph] from the packages in the sandbox.
 ///
 /// This graph will also include barback and its transitive dependencies from
 /// the repo.
 PackageGraph _loadPackageGraph() {
   // Load the sandbox packages.
   var packages = {};
 
   var systemCache = new SystemCache(p.join(sandboxDir, cachePath));
   systemCache.sources
       ..register(new PathSource())
       ..setDefault('path');
   var entrypoint = new Entrypoint(p.join(sandboxDir, appPath), systemCache);
 
   for (var package in listDir(sandboxDir)) {
     if (!fileExists(p.join(package, 'pubspec.yaml'))) continue;
     var packageName = p.basename(package);
-    packages[packageName] = new Package.load(
-        packageName, package, systemCache.sources);
+    packages[packageName] =
+        new Package.load(packageName, package, systemCache.sources);
   }
 
   loadPackage(packageName) {
     if (packages.containsKey(packageName)) return;
-    packages[packageName] = new Package.load(
-        packageName, packagePath(packageName), systemCache.sources);
+    packages[packageName] =
+        new Package.load(packageName, packagePath(packageName), systemCache.sources);
     for (var dep in packages[packageName].dependencies) {
       loadPackage(dep.name);
     }
   }
 
   loadPackage('barback');
 
   return new PackageGraph(entrypoint, null, packages);
 }
 
 /// Returns the contents of a no-op transformer that imports each URL in
 /// [imports].
 String transformer([Iterable<String> imports]) {
   if (imports == null) imports = [];
 
-  var buffer = new StringBuffer()
-      ..writeln('import "package:barback/barback.dart";');
+  var buffer =
+      new StringBuffer()..writeln('import "package:barback/barback.dart";');
   for (var import in imports) {
     buffer.writeln('import "$import";');
   }
 
   buffer.writeln("""
 NoOpTransformer extends Transformer {
   bool isPrimary(AssetId id) => true;
   void apply(Transform transform) {}
 }
 """);
 
   return buffer.toString();
 }