Use configurations and declared variables to select import/export URIs during prelinking.

pkg/analyzer/lib/src/summary/pub_summary.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.
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:core';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
@@ skipping 723 matching lines @@
         uriToNode[uri] = node;
       }
     }
     Set<String> libraryUris = uriToNode.keys.toSet();
     // Perform linking.
     Map<String, LinkedLibraryBuilder> linkedLibraries =
         link(libraryUris, (String uri) {
       return store.linkedMap[uri];
     }, (String uri) {
       return store.unlinkedMap[uri];
+    }, (String name) {
+      // TODO(scheglov) decide how to use declared variables in Pub
+      return null;
     }, strong);
     // Assemble linked bundles and put them into the store.
     for (_LinkedNode node in scc) {
       PackageBundleAssembler assembler = new PackageBundleAssembler();
       linkedLibraries.forEach((uri, linkedLibrary) {
         if (identical(uriToNode[uri], node)) {
           assembler.addLinkedLibrary(uri, linkedLibrary);
         }
       });
       List<int> bytes = assembler.assemble().toBuffer();
@@ skipping 21 matching lines @@
   }
 
   /**
    * Check whether the given `package:` [uri] is listed in the package map.
    */
   bool isListed(String uri) {
     String package = PubSummaryManager.getPackageName(uri);
     return names.contains(package);
   }
 }