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

pkg/front_end/lib/src/fasta/parser/listener.dart

Index: pkg/front_end/lib/src/fasta/parser/listener.dart
diff --git a/pkg/front_end/lib/src/fasta/parser/listener.dart b/pkg/front_end/lib/src/fasta/parser/listener.dart
index 3e74225ed889dbdf8244d9ef002a03666bfd1752..fc88cb4d5d6ed7aa014a91df920d45f4db511dac 100644
--- a/pkg/front_end/lib/src/fasta/parser/listener.dart
+++ b/pkg/front_end/lib/src/fasta/parser/listener.dart
@@ -551,7 +551,10 @@ class Listener {
   /// Handle the end of a "part of" directive.  Substructures:
   /// - Metadata
   /// - Library name (a qualified identifier)
-  void endPartOf(Token partKeyword, Token semicolon) {
+  ///
+  /// If [hasName] is true, this part refers to its library by name, otherwise,
+  /// by URI.
+  void endPartOf(Token partKeyword, Token semicolon, bool hasName) {
     logEvent("PartOf");
   }