Switch FE to use the libraries.json format.

pkg/front_end/test/src/incremental/file_state_test.dart

Index: pkg/front_end/test/src/incremental/file_state_test.dart
diff --git a/pkg/front_end/test/src/incremental/file_state_test.dart b/pkg/front_end/test/src/incremental/file_state_test.dart
index 2fd3a26c7be320e99611a47a4a47615161be720f..590b2d845ec98813d97fd0758dbae9b154375131 100644
--- a/pkg/front_end/test/src/incremental/file_state_test.dart
+++ b/pkg/front_end/test/src/incremental/file_state_test.dart
@@ -24,16 +24,14 @@ main() {
 class FileSystemStateTest {
   final byteStore = new MemoryByteStore();
   final fileSystem = new MemoryFileSystem(Uri.parse('file:///'));
-  final UriTranslatorImpl uriTranslator =
-      new UriTranslatorImpl({}, {}, Packages.noPackages);
   FileSystemState fsState;
 
   Uri _coreUri;
   List<Uri> _newFileUris = <Uri>[];
 
   void setUp() {
-    Map<String, Uri> dartLibraries = createSdkFiles(fileSystem);
-    uriTranslator.dartLibraries.addAll(dartLibraries);
+    var uriTranslator =
+        new UriTranslatorImpl(createSdkFiles(fileSystem), Packages.noPackages);
     _coreUri = Uri.parse('dart:core');
     expect(_coreUri, isNotNull);
     fsState = new FileSystemState(byteStore, fileSystem, uriTranslator, <int>[],