Cleanup namespace usage in platform/fonts/.

Source/platform/fonts/FontFamily.cpp

 /*
  * Copyright (C) 2004, 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 25 matching lines @@
     const FontFamily* bp;
     for (ap = a.next(), bp = b.next(); ap != bp; ap = ap->next(), bp = bp->next()) {
         if (!ap || !bp)
             return false;
         if (ap->family() != bp->family())
             return false;
     }
     return true;
 }
 
-}
+} // namespace blink