Enforce LinkedReference.dependency == 0 for contained entities.

pkg/analyzer/test/src/summary/summarize_ast_test.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 analyzer.test.src.summary.summarize_ast_test;
 
 import 'package:analyzer/analyzer.dart';
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/src/generated/error.dart';
 import 'package:analyzer/src/generated/parser.dart';
@@ skipping 74 matching lines @@
       }
       if (namespace == null && !allowMissingFiles) {
         fail('Prelinker unexpectedly requested namespace for "$relativeUri"'
             ' (resolves to "$absoluteUri").'
             '  Namespaces available: ${uriToUnit.keys}');
       }
       return namespace;
     }
     linked = new LinkedLibrary.fromBuffer(
         prelink(definingUnit, getPart, getImport).toBuffer());
+    validateLinkedLibrary(linked);
     unlinkedUnits = <UnlinkedUnit>[definingUnit];
     for (String relativeUri in definingUnit.publicNamespace.parts) {
       UnlinkedUnit unit = uriToUnit[resolveToAbsoluteUri(relativeUri)];
       if (unit == null) {
         if (!allowMissingFiles) {
           fail('Test referred to unknown unit $relativeUri');
         }
       } else {
         unlinkedUnits.add(unit);
       }
     }
   }
 
   CompilationUnit _parseText(String text) {
     CharSequenceReader reader = new CharSequenceReader(text);
     Scanner scanner =
         new Scanner(null, reader, AnalysisErrorListener.NULL_LISTENER);
     Token token = scanner.tokenize();
     Parser parser = new Parser(null, AnalysisErrorListener.NULL_LISTENER);
     parser.parseGenericMethods = true;
     return parser.parseCompilationUnit(token);
   }
 }