Move byte_store.dart and file_byte_store.dart to their own subdirectory.

pkg/analyzer/lib/src/dart/analysis/file_state.dart

 // Copyright (c) 2016, 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:convert';
 import 'dart:typed_data';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
@@ skipping 16 matching lines @@
 import 'package:analyzer/src/summary/name_filter.dart';
 import 'package:analyzer/src/summary/package_bundle_reader.dart';
 import 'package:analyzer/src/summary/summarize_ast.dart';
 import 'package:convert/convert.dart';
 import 'package:crypto/crypto.dart';
 import 'package:front_end/src/base/api_signature.dart';
 import 'package:front_end/src/base/performace_logger.dart';
 import 'package:front_end/src/fasta/builder/builder.dart' as fasta;
 import 'package:front_end/src/fasta/parser/parser.dart' as fasta;
 import 'package:front_end/src/fasta/scanner.dart' as fasta;
-import 'package:front_end/src/incremental/byte_store.dart';
+import 'package:front_end/src/byte_store/byte_store.dart';
 import 'package:meta/meta.dart';
 
 /**
  * [FileContentOverlay] is used to temporary override content of files.
  */
 class FileContentOverlay {
   final _map = <String, String>{};
 
   /**
    * Return the paths currently being overridden.
@@ skipping 895 matching lines @@
 
 /**
  * Information about changes to the known file set.
  */
 class KnownFilesSetChange {
   final Set<String> added;
   final Set<String> removed;
 
   KnownFilesSetChange(this.added, this.removed);
 }