Switch FE to use the libraries.json format.

pkg/front_end/test/src/incremental/hot_reload_e2e_test.dart

Index: pkg/front_end/test/src/incremental/hot_reload_e2e_test.dart
diff --git a/pkg/front_end/test/src/incremental/hot_reload_e2e_test.dart b/pkg/front_end/test/src/incremental/hot_reload_e2e_test.dart
index 0740dfc52150f164f9b4d3abb985b2d0e3f9e799..0571ed8efcc70b29c3e686495512c01d8619ce69 100644
--- a/pkg/front_end/test/src/incremental/hot_reload_e2e_test.dart
+++ b/pkg/front_end/test/src/incremental/hot_reload_e2e_test.dart
@@ -175,24 +175,14 @@ Future<IncrementalKernelGenerator> createIncrementalCompiler(
   var entryUri = Uri.base.resolve(entry);
   var options = new CompilerOptions()
     ..sdkRoot = sdkRoot
-    ..sdkSummary = sdkRoot.resolve('outline.dill')
     ..packagesFileUri = Uri.parse('file:///.packages')
     ..strongMode = false
-    ..dartLibraries = loadDartLibraries()
+    ..compileSdk = true // the incremental generator requires the sdk sources
     ..fileSystem = fs
     ..byteStore = new MemoryByteStore();
   return IncrementalKernelGenerator.newInstance(options, entryUri);
 }
 
-Map<String, Uri> loadDartLibraries() {
-  var libraries = sdkRoot.resolve('lib/libraries.json');
-  var map =
-      JSON.decode(new File.fromUri(libraries).readAsStringSync())['libraries'];
-  var dartLibraries = <String, Uri>{};
-  map.forEach((k, v) => dartLibraries[k] = libraries.resolve(v));
-  return dartLibraries;
-}
-
 Future<bool> rebuild(IncrementalKernelGenerator compiler, Uri outputUri) async {
   compiler.invalidate(Uri.parse("file:///a.dart"));
   compiler.invalidate(Uri.parse("file:///b.dart"));