Remove code that requires whole-program compile

lib/src/transformer/asset_universe.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 dev_compiler.src.transformer.asset_universe;
-
-import 'dart:async';
-
-import 'package:analyzer/analyzer.dart' show UriBasedDirective, parseDirectives;
-import 'package:barback/barback.dart' show Asset, AssetId;
-
-import 'asset_source.dart';
-import 'uri_resolver.dart' show assetIdToUri, resolveAssetId;
-
-/// Set of assets sources available for analysis / compilation.
-class AssetUniverse {
-  final _assetCache = <AssetId, AssetSource>{};
-
-  Iterable<AssetId> get assetIds => _assetCache.keys;
-
-  AssetSource getAssetSource(AssetId id) {
-    var source = _assetCache[id];
-    if (source == null) {
-      throw new ArgumentError(id.toString());
-    }
-    return source;
-  }
-
-  /// Recursively loads the asset with [id] and all its transitive dependencies.
-  Future scanSources(AssetId id, Future<Asset> getInput(AssetId id)) async {
-    if (_assetCache.containsKey(id)) return;
-
-    var asset = await getInput(id);
-    var contents = await asset.readAsString();
-    _assetCache[id] =
-        new AssetSource(Uri.parse(assetIdToUri(id)), asset, contents);
-
-    var deps = _getDependentAssetIds(id, contents);
-    await Future.wait(deps.map((depId) => scanSources(depId, getInput)));
-  }
-
-  Iterable<AssetId> _getDependentAssetIds(AssetId id, String contents) sync* {
-    var directives = parseDirectives(contents, suppressErrors: true).directives;
-    for (var directive in directives) {
-      if (directive is UriBasedDirective) {
-        var uri = directive.uri.stringValue;
-        var assetId = resolveAssetId(Uri.parse(uri), fromAssetId: id);
-        if (assetId != null) yield assetId;
-      }
-    }
-  }
-}