Refactor CompilerOutput

tests/compiler/dart2js/sourcemaps/nomapping_test.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.
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
 
 import 'package:async_helper/async_helper.dart';
 import 'package:compiler/compiler_new.dart';
@@ skipping 59 matching lines @@
   if (useNewSourceInfo) {
     options.add(Flags.useNewSourceInfo);
   }
   CompilationResult compilationResult = await runCompiler(
       entryPoint: Uri.parse('memory:main.dart'),
       memorySourceFiles: {'main.dart': code},
       outputProvider: collector,
       options: options);
   Expect.isTrue(compilationResult.isSuccess,
       "Unsuccessful compilation of test:\n${code}");
-  String sourceMapText = collector.getOutput('', 'js.map');
+  String sourceMapText = collector.getOutput('', OutputType.sourceMap);
   SingleMapping sourceMap = parse(sourceMapText);
   if (writeJs) {
-    new File('out.js').writeAsStringSync(collector.getOutput('', 'js'));
+    new File('out.js')
+        .writeAsStringSync(collector.getOutput('', OutputType.js));
     new File('out.js.map').writeAsStringSync(sourceMapText);
   }
   Expect.isTrue(sourceMap.lines.isNotEmpty);
   TargetLineEntry firstLineEntry = sourceMap.lines.first;
   Expect.isTrue(firstLineEntry.entries.isNotEmpty);
   TargetEntry firstEntry = firstLineEntry.entries.first;
   Expect.isNull(
       firstEntry.sourceUrlId,
       "Unexpected first entry: "
       "${entryToString(firstLineEntry, firstEntry, sourceMap)}");
@@ skipping 26 matching lines @@
   }
   if (entry.sourceLine != null) {
     sb.write('sourceLine=');
     sb.write(entry.sourceLine);
     sb.write(',sourceColumn=');
     sb.write(entry.sourceColumn);
   }
   sb.write(']');
   return sb.toString();
 }