pkg/compiler: fix imports

pkg/compiler/lib/src/scanner/scanner.dart

 // Copyright (c) 2012, 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 dart2js.scanner;
 
 import '../io/source_file.dart' show SourceFile, Utf8BytesSourceFile;
 import '../tokens/keyword.dart' show Keyword, KeywordState;
 import '../tokens/precedence.dart';
 import '../tokens/precedence_constants.dart';
 import '../tokens/token.dart';
 import '../tokens/token_constants.dart';
 import '../util/characters.dart';
-
 import 'string_scanner.dart' show StringScanner;
 import 'utf8_bytes_scanner.dart' show Utf8BytesScanner;
 
 abstract class Scanner {
   Token tokenize();
 
   factory Scanner(SourceFile file, {bool includeComments: false}) {
     if (file is Utf8BytesSourceFile) {
       return new Utf8BytesScanner(file, includeComments: includeComments);
     } else {
@@ skipping 1152 matching lines @@
 
 PrecedenceInfo closeBraceInfoFor(BeginGroupToken begin) {
   return const {
     '(': CLOSE_PAREN_INFO,
     '[': CLOSE_SQUARE_BRACKET_INFO,
     '{': CLOSE_CURLY_BRACKET_INFO,
     '<': GT_INFO,
     r'${': CLOSE_CURLY_BRACKET_INFO,
   }[begin.value];
 }