Clear 'referenceMap' before summarizing a new unit.

pkg/analyzer/lib/src/summary/summarize_elements.dart

 // Copyright (c) 2015, 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 serialization.elements;
 
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/type.dart';
 import 'package:analyzer/src/dart/element/type.dart';
 import 'package:analyzer/src/generated/resolver.dart';
@@ skipping 138 matching lines @@
   LibraryElement get coreLibrary => typeProvider.objectType.element.library;
 
   /**
    * Add all classes, enums, typedefs, executables, and top level variables
    * from the given compilation unit [element] to the library summary.
    * [unitNum] indicates the ordinal position of this compilation unit in the
    * library.
    */
   void addCompilationUnitElements(CompilationUnitElement element, int unitNum) {
     UnlinkedUnitBuilder b = new UnlinkedUnitBuilder(ctx);
+    referenceMap.clear();
     unlinkedReferences = <UnlinkedReferenceBuilder>[
       encodeUnlinkedReference(ctx)
     ];
     prelinkedReferences = <PrelinkedReferenceBuilder>[
       encodePrelinkedReference(ctx, kind: PrelinkedReferenceKind.classOrEnum)
     ];
     if (unitNum == 0) {
       // TODO(paulberry): we need to figure out a way to record library, part,
       // import, and export declarations that appear in non-defining
       // compilation units (even though such declarations are prohibited by the
@@ skipping 435 matching lines @@
     UnlinkedVariableBuilder b = new UnlinkedVariableBuilder(ctx);
     b.name = variable.name;
     b.type = serializeTypeRef(variable.type, variable);
     b.isStatic = variable.isStatic && variable.enclosingElement is ClassElement;
     b.isFinal = variable.isFinal;
     b.isConst = variable.isConst;
     b.hasImplicitType = variable.hasImplicitType;
     return b;
   }
 }