Add --use-new-source-info option

tests/compiler/dart2js/sourcemaps/sourcemap_helper.dart

 // Copyright (c) 2015, 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 sourcemap.helper;
 
 import 'dart:async';
 import 'dart:io';
 import 'package:compiler/compiler_new.dart';
 import 'package:compiler/src/apiimpl.dart' as api;
+import 'package:compiler/src/commandline_options.dart';
 import 'package:compiler/src/null_compiler_output.dart' show NullSink;
 import 'package:compiler/src/elements/elements.dart';
 import 'package:compiler/src/helpers/helpers.dart';
 import 'package:compiler/src/filenames.dart';
 import 'package:compiler/src/io/code_output.dart';
 import 'package:compiler/src/io/source_file.dart';
 import 'package:compiler/src/io/source_information.dart';
 import 'package:compiler/src/io/position_information.dart';
 import 'package:compiler/src/js/js.dart' as js;
 import 'package:compiler/src/js/js_debug.dart';
@@ skipping 243 matching lines @@
     if (add) {
       nodes.add(node);
     }
     node.visitChildren(this);
     if (node == soughtNode) {
       add = false;
     }
   }
 }
 
-const String USE_NEW_SOURCE_INFO =  '--use-new-source-info';
 const String DISABLE_INLINING = '--disable-inlining';
 
 /// Processor that computes [SourceMapInfo] for the JavaScript compiled for a
 /// given Dart file.
 class SourceMapProcessor {
   /// If `true` the output from the compilation is written to files.
   final bool outputToFile;
 
   /// The [Uri] of the Dart entrypoint.
   Uri inputUri;
@@ skipping 20 matching lines @@
 
   /// Computes the [SourceMapInfo] for the compiled elements.
   Future<SourceMaps> process(
       List<String> options,
       {bool verbose: true,
        bool perElement: true,
        bool forMain: false}) async {
     OutputProvider outputProvider = outputToFile
         ? new CloningOutputProvider(targetUri, sourceMapFileUri)
         : new OutputProvider();
-    if (options.contains(USE_NEW_SOURCE_INFO)) {
+    if (options.contains(Flags.useNewSourceInfo)) {
       if (verbose) print('Using the new source information system.');
-      useNewSourceInfo = true;
     }
     api.CompilerImpl compiler = await compilerFor(
         outputProvider: outputProvider,
         // TODO(johnniwinther): Use [verbose] to avoid showing diagnostics.
         options: ['--out=$targetUri', '--source-map=$sourceMapFileUri']
             ..addAll(options));
     if (options.contains(DISABLE_INLINING)) {
       if (verbose) print('Inlining disabled');
       compiler.disableInlining = true;
     }
@@ skipping 260 matching lines @@
       absoluteUri = base.resolveUri(uri);
     } else {
       absoluteUri = base.resolve(uri);
     }
     return sourceFiles.putIfAbsent(absoluteUri, () {
       String text = new File.fromUri(absoluteUri).readAsStringSync();
       return new StringSourceFile.fromUri(absoluteUri, text);
     });
   }
 }