Change dependency walker's Node.dependencies to a static getter.

pkg/analyzer/lib/src/summary/link.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.
 
 /**
  * This library is capable of producing linked summaries from unlinked
  * ones (or prelinked ones).  It functions by building a miniature
  * element model to represent the contents of the summaries, and then
  * scanning the element model to gather linked information and adding
  * it to the summary data structures.
@@ skipping 3404 matching lines @@
  * Specialization of [DependencyWalker] for computing library cycles.
  */
 class LibraryDependencyWalker extends DependencyWalker<LibraryNode> {
   @override
   void evaluate(LibraryNode v) => evaluateScc(<LibraryNode>[v]);
 
   @override
   void evaluateScc(List<LibraryNode> scc) {
     Set<LibraryCycleForLink> dependentCycles = new Set<LibraryCycleForLink>();
     for (LibraryNode node in scc) {
-      for (LibraryNode dependency in node.dependencies) {
+      for (LibraryNode dependency in Node.getDependencies(node)) {
         if (dependency.isEvaluated) {
           dependentCycles.add(dependency._libraryCycle);
         }
       }
     }
     LibraryCycleForLink cycle = new LibraryCycleForLink(
         scc.map((LibraryNode n) => n.library).toList(),
         dependentCycles.toList());
     for (LibraryNode node in scc) {
       node._libraryCycle = cycle;
@@ skipping 1874 matching lines @@
 }
 
 /**
  * This exception is thrown when [ExprTypeComputer] cannot inference the type.
  */
 class _InferenceFailedError {
   final String message;
 
   _InferenceFailedError(this.message);
 }