Add more missing closing namespace comments.

third_party/WebKit/Source/core/layout/LayoutScrollbarPart.cpp

 /*
  * Copyright (C) 2008 Apple 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 196 matching lines @@
         if (frameView->isFrameViewScrollCorner(this)) {
             frameView->setScrollCornerNeedsPaintInvalidation();
             return;
         }
     }
 
     // This LayoutScrollbarPart belongs to a PaintLayerScrollableArea.
     toLayoutBox(parent())->scrollableArea()->setScrollCornerNeedsPaintInvalidation();
 }
 
-}
+} // namespace blink