Make backend and reporter customizable.

pkg/compiler/lib/src/apiimpl.dart

 // Copyright (c) 2012, 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 leg_apiimpl;
 
 import 'dart:async';
 import 'dart:convert';
 
 import 'package:package_config/packages.dart';
 import 'package:package_config/packages_file.dart' as pkgs;
 import 'package:package_config/src/packages_impl.dart'
     show MapPackages, NonFilePackagesDirectoryPackages;
 import 'package:package_config/src/util.dart' show checkValidPackageUri;
 
 import '../compiler_new.dart' as api;
 import 'common/tasks.dart' show GenericTask;
 import 'common.dart';
+import 'common/backend_api.dart' show
+    Backend;
 import 'compiler.dart';
 import 'diagnostics/messages.dart' show Message;
 import 'elements/elements.dart' as elements;
 import 'environment.dart';
 import 'io/source_file.dart';
 import 'options.dart' show CompilerOptions;
 import 'platform_configuration.dart' as platform_configuration;
 import 'resolved_uri_translator.dart';
 import 'script.dart';
 
@@ skipping 10 matching lines @@
 
   ForwardingResolvedUriTranslator resolvedUriTranslator;
 
   GenericTask userHandlerTask;
   GenericTask userProviderTask;
   GenericTask userPackagesDiscoveryTask;
 
   Uri get libraryRoot => options.platformConfigUri.resolve(".");
 
   CompilerImpl(this.provider, api.CompilerOutput outputProvider, this.handler,
-      CompilerOptions options)
+      CompilerOptions options,
+      {MakeBackendFuncion makeBackend, MakeReporterFunction makeReporter})
       : resolvedUriTranslator = new ForwardingResolvedUriTranslator(),
         super(
             options: options,
             outputProvider: outputProvider,
-            environment: new _Environment(options.environment)) {
+            environment: new _Environment(options.environment),
+            makeBackend: makeBackend, makeReporter: makeReporter) {
     _Environment env = environment;
     env.compiler = this;
     tasks.addAll([
       userHandlerTask = new GenericTask('Diagnostic handler', this),
       userProviderTask = new GenericTask('Input provider', this),
       userPackagesDiscoveryTask = new GenericTask('Package discovery', this),
     ]);
   }
 
   void log(message) {
@@ skipping 284 matching lines @@
   }
 }
 
 /// For every 'dart:' library, a corresponding environment variable is set
 /// to "true". The environment variable's name is the concatenation of
 /// this prefix and the name (without the 'dart:'.
 ///
 /// For example 'dart:html' has the environment variable 'dart.library.html' set
 /// to "true".
 const String _dartLibraryEnvironmentPrefix = 'dart.library.';