Removed fixed dependencies

packages/html/lib/src/tokenizer.dart

 library tokenizer;
 
 import 'dart:collection';
 import 'package:html/parser.dart' show HtmlParser;
 import 'constants.dart';
 import 'inputstream.dart';
 import 'token.dart';
 import 'utils.dart';
 
 // Group entities by their first character, for faster lookups
 
 // TODO(jmesserly): we could use a better data structure here like a trie, if
 // we had it implemented in Dart.
 Map<String, List<String>> entitiesByFirstChar = (() {
-  var result = {};
+  var result = <String, List<String>>{};
   for (var k in entities.keys) {
     result.putIfAbsent(k[0], () => []).add(k);
   }
   return result;
 })();
 
 // TODO(jmesserly): lots of ways to make this faster:
 // - use char codes everywhere instead of 1-char strings
 // - use switch instead of contains, indexOf
 // - use switch instead of the sequential if tests
@@ skipping 1873 matching lines @@
       }
     }
 
     if (data.length > 0) {
       _addToken(new CharactersToken(data.join()));
     }
     state = dataState;
     return true;
   }
 }