Add more missing closing namespace comments.

third_party/WebKit/Source/core/dom/LayoutTreeBuilderTraversal.cpp

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Neither the name of Google Inc. nor the names of its
@@ skipping 229 matching lines @@
     const WillBeHeapVector<RefPtrWillBeMember<Element>>& topLayerElements = element.document().topLayerElements();
     size_t position = topLayerElements.find(&element);
     ASSERT(position != kNotFound);
     for (size_t i = position + 1; i < topLayerElements.size(); ++i) {
         if (LayoutObject* layoutObject = topLayerElements[i]->layoutObject())
             return layoutObject;
     }
     return 0;
 }
 
-}
+} // namespace LayoutTreeBuilderTraversal
 
-} // namespace
+} // namespace blink