Refactor CompilerOutput

tests/compiler/dart2js/sourcemaps/mapping_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 120 matching lines @@
   if (useNewSourceInfo) {
     options.add(Flags.useNewSourceInfo);
   }
   CompilationResult compilationResult = await runCompiler(
       entryPoint: Uri.parse('memory:main.dart'),
       memorySourceFiles: {'main.dart': test.code},
       outputProvider: collector,
       options: options);
   Expect.isTrue(compilationResult.isSuccess,
       "Unsuccessful compilation of test:\n${test.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);
   }
 
   Set<SourceLocation> expectedLocations = test.expectedLocations.toSet();
   List<SourceLocation> actualLocations = <SourceLocation>[];
   List<SourceLocation> extraLocations = <SourceLocation>[];
   for (TargetLineEntry targetLineEntry in sourceMap.lines) {
     for (TargetEntry targetEntry in targetLineEntry.entries) {
       if (targetEntry.sourceUrlId != null &&
           sourceMap.urls[targetEntry.sourceUrlId] == 'memory:main.dart') {
@@ skipping 52 matching lines @@
   bool operator ==(other) {
     if (identical(this, other)) return true;
     if (other is! SourceLocation) return false;
     return methodName == other.methodName &&
         lineNo == other.lineNo &&
         columnNo == other.columnNo;
   }
 
   String toString() => '$methodName:$lineNo:$columnNo';
 }