Remove package imports from itself.

pkg/front_end/lib/src/fasta/analyzer/token_utils.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.
 
 library fasta.analyzer.token_utils;
 
-import 'package:front_end/src/fasta/parser/error_kind.dart' show ErrorKind;
+import '../parser/error_kind.dart' show ErrorKind;
 
-import 'package:front_end/src/fasta/scanner/error_token.dart' show ErrorToken;
+import '../scanner/error_token.dart' show ErrorToken;
 
-import 'package:front_end/src/fasta/scanner/keyword.dart' show Keyword;
+import '../scanner/keyword.dart' show Keyword;
 
-import 'package:front_end/src/fasta/scanner/precedence.dart';
+import '../scanner/precedence.dart';
 
-import 'package:front_end/src/fasta/scanner/token.dart'
+import '../scanner/token.dart'
     show BeginGroupToken, KeywordToken, StringToken, SymbolToken, Token;
 
-import 'package:front_end/src/fasta/scanner/token_constants.dart';
+import '../scanner/token_constants.dart';
 
-import 'package:front_end/src/scanner/token.dart' as analyzer
+import '../../scanner/token.dart' as analyzer
     show
         BeginToken,
         BeginTokenWithComment,
         CommentToken,
         Keyword,
         KeywordToken,
         KeywordTokenWithComment,
         StringToken,
         StringTokenWithComment,
         Token,
         TokenWithComment;
 
-import 'package:front_end/src/scanner/errors.dart' as analyzer
-    show ScannerErrorCode;
+import '../../scanner/errors.dart' as analyzer show ScannerErrorCode;
 
 import 'package:analyzer/dart/ast/token.dart' show TokenType;
 
 import '../errors.dart' show internalError;
 
 /// Class capable of converting a stream of Fasta tokens to a stream of analyzer
 /// tokens.
 ///
 /// This is a class rather than an ordinary method so that it can be subclassed
 /// in tests.
@@ skipping 720 matching lines @@
     case PERIOD_PERIOD_PERIOD_TOKEN:
       return TokenType.PERIOD_PERIOD_PERIOD;
     // case GENERIC_METHOD_TYPE_LIST_TOKEN:
     //   return TokenType.GENERIC_METHOD_TYPE_LIST;
     // case GENERIC_METHOD_TYPE_ASSIGN_TOKEN:
     //   return TokenType.GENERIC_METHOD_TYPE_ASSIGN;
     default:
       return internalError("Unhandled token ${token.info}");
   }
 }