Add FrontEndStrategy, ResolutionFrontEndStrategy and KernelFrontEndStrategy

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 '../common.dart';
+import '../common_elements.dart';
+import '../common/tasks.dart';
+import '../environment.dart' as env;
+import '../frontend_strategy.dart';
+import '../library_loader.dart';
+import '../serialization/task.dart';
+import '../patch_parser.dart';
+import '../resolved_uri_translator.dart';
+import 'world_builder.dart';
+
+/// Front end strategy that loads '.dill' files and builds a resolved element
+/// model from kernel IR nodes.
+class KernelFrontEndStrategy implements FrontEndStrategy {
+  KernelWorldBuilder worldBuilder;
+
+  KernelAnnotationProcessor _annotationProcesser;
+
+  KernelFrontEndStrategy(DiagnosticReporter reporter)
+      : worldBuilder = new KernelWorldBuilder(reporter);
+
+  @override
+  LibraryLoaderTask createLibraryLoader(
+      ResolvedUriTranslator uriTranslator,
+      ScriptLoader scriptLoader,
+      ElementScanner scriptScanner,
+      LibraryDeserializer deserializer,
+      PatchResolverFunction patchResolverFunc,
+      PatchParserTask patchParser,
+      env.Environment environment,
+      DiagnosticReporter reporter,
+      Measurer measurer) {
+    return new DillLibraryLoaderTask(
+        worldBuilder, uriTranslator, scriptLoader, reporter, measurer);
+  }
+
+  @override
+  ElementEnvironment get elementEnvironment => worldBuilder.elementEnvironment;
+
+  @override
+  AnnotationProcessor get annotationProcesser =>
+      _annotationProcesser ??= new KernelAnnotationProcessor(worldBuilder);
+}