Recompile unit with potential conflict/dependency on some top-level symbol.

compiler/javatests/com/google/dart/compiler/parser/AbstractParserTest.java

 // Copyright (c) 2011, 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.
 
 package com.google.dart.compiler.parser;
 
 import com.google.dart.compiler.CompilerTestCase;
 import com.google.dart.compiler.ast.DartDirective;
 import com.google.dart.compiler.ast.DartImportDirective;
 import com.google.dart.compiler.ast.DartLibraryDirective;
@@ skipping 140 matching lines @@
     }
     String megaSource = out.toString();
     long start = System.currentTimeMillis();
     parseUnit("Mega.dart", megaSource);
     System.out.format("%s ms for '%s.%s()'%n", System.currentTimeMillis() - start,
                       getClass().getName(), getName());
   }
 
   @Override
   protected DartParser makeParser(ParserContext context) {
-    Set<String> set = new HashSet<String>();
-    set.add("prefix");
-    return new DartParser(context, set);
+    Set<String> prefixes = new HashSet<String>();
+    prefixes.add("prefix");
+    return new DartParser(context, prefixes, false);
   }
 }