Add support for compiling Dart via the FE in dart2js.

pkg/compiler/lib/src/kernel/kernel_strategy.dart

 // Copyright (c) 2017, 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 dart2js.kernel.frontend_strategy;
 
+import '../../compiler_new.dart' as api;
 import '../common.dart';
 import '../common_elements.dart';
 import '../common/backend_api.dart';
 import '../common/resolution.dart';
 import '../common/tasks.dart';
 import '../common/work.dart';
 import '../elements/elements.dart';
 import '../elements/entities.dart';
 import '../elements/types.dart';
 import '../environment.dart' as env;
@@ skipping 30 matching lines @@
 
   KernelFrontEndStrategy(
       this._options, DiagnosticReporter reporter, env.Environment environment)
       : _elementMap =
             new KernelToElementMapForImpactImpl(reporter, environment);
 
   @override
   LibraryLoaderTask createLibraryLoader(
       ResolvedUriTranslator uriTranslator,
       ScriptLoader scriptLoader,
+      api.CompilerInput compilerInput,
       ElementScanner scriptScanner,
       LibraryDeserializer deserializer,
       PatchResolverFunction patchResolverFunc,
       PatchParserTask patchParser,
       env.Environment environment,
       DiagnosticReporter reporter,
       Measurer measurer) {
-    return new DillLibraryLoaderTask(
-        _elementMap, uriTranslator, scriptLoader, reporter, measurer);
+    return new KernelLibraryLoaderTask(
+        _elementMap, compilerInput, reporter, measurer);
   }
 
   @override
   ElementEnvironment get elementEnvironment => _elementMap.elementEnvironment;
 
   @override
   CommonElements get commonElements => _elementMap.commonElements;
 
   DartTypes get dartTypes => _elementMap.types;
 
@@ skipping 150 matching lines @@
   int get preMirrorsMethodCount {
     // TODO(redemption): Implement this.
     return null;
   }
 
   @override
   void onQueueEmpty(Enqueuer enqueuer, Iterable<ClassEntity> recentClasses) {
     // TODO(redemption): Implement this.
   }
 }