Issue 3931. Visit children nodes safely.

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

Index: compiler/java/com/google/dart/compiler/ast/DartTryStatement.java
diff --git a/compiler/java/com/google/dart/compiler/ast/DartTryStatement.java b/compiler/java/com/google/dart/compiler/ast/DartTryStatement.java
index 4357f92fffdfe46a6dcebe8aefb016a7096b68c2..14f542f7489531b7cc64f95e81ebee7566ada14a 100644
--- a/compiler/java/com/google/dart/compiler/ast/DartTryStatement.java
+++ b/compiler/java/com/google/dart/compiler/ast/DartTryStatement.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.
 
@@ -36,11 +36,9 @@ public class DartTryStatement extends DartStatement {
 
   @Override
   public void visitChildren(ASTVisitor<?> visitor) {
-    tryBlock.accept(visitor);
+    safelyVisitChild(tryBlock, visitor);
     catchBlocks.accept(visitor);
-    if (finallyBlock != null) {
-      finallyBlock.accept(visitor);
-    }
+    safelyVisitChild(finallyBlock, visitor);
   }
 
   @Override