Issue 3931. Visit children nodes safely.

compiler/java/com/google/dart/compiler/ast/DartReturnStatement.java

Index: compiler/java/com/google/dart/compiler/ast/DartReturnStatement.java
diff --git a/compiler/java/com/google/dart/compiler/ast/DartReturnStatement.java b/compiler/java/com/google/dart/compiler/ast/DartReturnStatement.java
index 2ab304ee85b80b09264fe9f0f0a4ae4b59f30974..8148fcc964f47eab53427a11a2e4f1063f46036c 100644
--- a/compiler/java/com/google/dart/compiler/ast/DartReturnStatement.java
+++ b/compiler/java/com/google/dart/compiler/ast/DartReturnStatement.java
@@ -1,4 +1,4 @@
-// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
+// Copyright (c) 2012, 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.
 
@@ -26,9 +26,7 @@ public class DartReturnStatement extends DartStatement {
 
   @Override
   public void visitChildren(ASTVisitor<?> visitor) {
-    if (value != null) {
-      value.accept(visitor);
-    }
+    safelyVisitChild(value, visitor);
   }
 
   @Override