Revert "Switch FE to use the libraries.json format."

pkg/front_end/lib/incremental_kernel_generator.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.
 
 import 'dart:async';
 
 import 'package:front_end/src/base/processed_options.dart';
 import 'package:front_end/src/incremental_kernel_generator_impl.dart';
-import 'package:front_end/src/fasta/compiler_context.dart';
 import 'package:kernel/kernel.dart';
 
 import 'compiler_options.dart';
 
 /// The type of the function that clients can pass to track used files.
 ///
 /// When a file is first used during compilation, this function is called with
 /// the [Uri] of that file and [used] == `true`. The content of the file is not
 /// read until the [Future] returned by the function completes. If, during a
 /// subsequent compilation, a file that was being used is no longer used, then
@@ skipping 74 matching lines @@
   /// kernel representations of the program whose main library is in the given
   /// [entryPoint].
   ///
   /// The initial "previous program state" is an empty program containing no
   /// code, and the initial set of valid sources is empty.  To obtain a kernel
   /// representation of the program, call [computeDelta].
   static Future<IncrementalKernelGenerator> newInstance(
       CompilerOptions options, Uri entryPoint,
       {WatchUsedFilesFn watch}) async {
     var processedOptions = new ProcessedOptions(options, false, [entryPoint]);
-    return await CompilerContext.runWithOptions(processedOptions, (_) async {
-      var uriTranslator = await processedOptions.getUriTranslator();
-      return new IncrementalKernelGeneratorImpl(
-          processedOptions, uriTranslator, entryPoint,
-          watch: watch);
-    });
+    var uriTranslator = await processedOptions.getUriTranslator();
+    return new IncrementalKernelGeneratorImpl(
+        processedOptions, uriTranslator, entryPoint,
+        watch: watch);
   }
 }