Handle 'part of' declarations with URI correctly in Fasta.

pkg/front_end/lib/src/fasta/analyzer/ast_builder.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.ast_builder;
 
 import 'package:analyzer/analyzer.dart';
 import 'package:analyzer/dart/ast/ast_factory.dart' show AstFactory;
 import 'package:analyzer/dart/ast/standard_ast_factory.dart' as standard;
 import 'package:analyzer/dart/ast/token.dart' as analyzer show Token;
@@ skipping 1144 matching lines @@
   void endPart(Token partKeyword, Token semicolon) {
     debugEvent("Part");
     StringLiteral uri = pop();
     List<Annotation> metadata = pop();
     Comment comment = pop();
     push(ast.partDirective(comment, metadata, toAnalyzerToken(partKeyword), uri,
         toAnalyzerToken(semicolon)));
   }
 
   @override
-  void endPartOf(Token partKeyword, Token semicolon) {
+  void endPartOf(Token partKeyword, Token semicolon, bool hasName) {
     debugEvent("PartOf");
     List<SimpleIdentifier> libraryName = pop();
     var name = ast.libraryIdentifier(libraryName);
     StringLiteral uri = null; // TODO(paulberry)
     // TODO(paulberry,ahe): seems hacky.  It would be nice if the parser passed
     // in a reference to the "of" keyword.
     var ofKeyword = partKeyword.next;
     List<Annotation> metadata = pop();
     Comment comment = pop();
     push(ast.partOfDirective(comment, metadata, toAnalyzerToken(partKeyword),
@@ skipping 413 matching lines @@
       } else if (identical('static', s)) {
         staticKeyword = token;
       } else if (identical('var', s)) {
         finalConstOrVarKeyword = token;
       } else {
         internalError('Unhandled modifier: $s');
       }
     }
   }
 }