Load extraRequiredLibraries from the target passed in the options

pkg/front_end/lib/src/incremental/file_state.dart

Index: pkg/front_end/lib/src/incremental/file_state.dart
diff --git a/pkg/front_end/lib/src/incremental/file_state.dart b/pkg/front_end/lib/src/incremental/file_state.dart
index d060d02e7849f534c2037fcd3378235641b7c662..cb0a0d6d44254af58f384173d25a2bb8dc5431e7 100644
--- a/pkg/front_end/lib/src/incremental/file_state.dart
+++ b/pkg/front_end/lib/src/incremental/file_state.dart
@@ -15,7 +15,7 @@ import 'package:front_end/src/fasta/uri_translator.dart';
 import 'package:front_end/src/byte_store/byte_store.dart';
 import 'package:front_end/src/incremental/format.dart';
 import 'package:front_end/src/incremental/unlinked_unit.dart';
-import 'package:kernel/target/vm.dart';
+import 'package:kernel/target/targets.dart';
 
 /// This function is called for each newly discovered file, and the returned
 /// [Future] is awaited before reading the file content.
@@ -182,7 +182,7 @@ class FileState {
         _importedLibraries.add(file);
       }
     }
-    await _addVmTargetImportsForCore();
+    await _addTargetExtraRequiredLibraries();
     for (var export_ in unlinkedUnit.exports) {
       FileState file = await _getFileForRelativeUri(export_.uri);
       if (file != null) {
@@ -228,13 +228,14 @@ class FileState {
     return uri.toString();
   }
 
-  /// Fasta unconditionally loads all VM libraries.  In order to be able to
-  /// serve them using the file system view, pretend that all of them were
-  /// imported into `dart:core`.
-  /// TODO(scheglov) Ask VM people whether all these libraries are required.
-  Future<Null> _addVmTargetImportsForCore() async {
+  /// Fasta unconditionally loads extra libraries based on the target.  In order
+  /// to be able to serve them using the file system view, pretend that all of
+  /// them were imported into `dart:core`.
+  /// TODO(scheglov,sigmund): remove this implicit import, instead make fasta
+  /// and IKG aware of extra code that needs to be loaded.
+  Future<Null> _addTargetExtraRequiredLibraries() async {
     if (uri.toString() != 'dart:core') return;
-    for (String uri in new VmTarget(null).extraRequiredLibraries) {
+    for (String uri in _fsState.target.extraRequiredLibraries) {
       FileState file = await _getFileForRelativeUri(uri);
       // TODO(scheglov) add error handling
       if (file != null) {
@@ -267,6 +268,7 @@ class FileState {
 class FileSystemState {
   final ByteStore _byteStore;
   final FileSystem fileSystem;
+  final Target target;
   final UriTranslator uriTranslator;
   final List<int> _salt;
   final NewFileFn _newFileFn;
@@ -285,8 +287,8 @@ class FileSystemState {
   /// We do this when we use SDK outline instead of compiling SDK sources.
   final Set<Uri> skipSdkLibraries = new Set<Uri>();
 
-  FileSystemState(this._byteStore, this.fileSystem, this.uriTranslator,
-      this._salt, this._newFileFn);
+  FileSystemState(this._byteStore, this.fileSystem, this.target,
+      this.uriTranslator, this._salt, this._newFileFn);
 
   /// Return the [FileSystem] that is backed by this [FileSystemState].  The
   /// files in this [FileSystem] always have the same content as the