Prepare for development branch by updating externally-used API.

pkg/front_end/lib/src/incremental_kernel_generator_impl.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 'dart:io';
 
 import 'package:front_end/file_system.dart';
 import 'package:front_end/incremental_kernel_generator.dart';
 import 'package:front_end/src/base/api_signature.dart';
@@ skipping 228 matching lines @@
   /// TODO(scheglov) Remove/replace this when Kernel has export scopes.
   void _computeExportScopes(DillTarget dillTarget,
       Map<Uri, FileState> uriToFile, List<DillLibraryBuilder> libraries) {
     bool wasChanged = false;
     do {
       wasChanged = false;
       for (DillLibraryBuilder library in libraries) {
         FileState file = uriToFile[library.uri];
         for (NamespaceExport export in file.exports) {
           DillLibraryBuilder exportedLibrary =
-              dillTarget.loader.read(export.library.uri);
+              dillTarget.loader.read(export.library.uri, -1, accessor: library);
           if (exportedLibrary != null) {
             exportedLibrary.exports.forEach((name, member) {
               if (export.isExposed(name) &&
                   library.addToExportScope(name, member)) {
                 wasChanged = true;
               }
             });
           } else {
             // TODO(scheglov) How to handle this?
           }
@@ skipping 42 matching lines @@
   /// TODO(scheglov) Use API signatures.
   /// TODO(scheglov) Or use tree shaking and compute signatures of outlines.
   final String signature;
 
   /// Kernel libraries for libraries in the [cycle].  Bodies of dependencies
   /// are not included, but but references to those dependencies are included.
   final List<Library> kernelLibraries;
 
   _LibraryCycleResult(this.cycle, this.signature, this.kernelLibraries);
 }