third_party/protobuf: Update to HEAD (f52e188fe4)

third_party/protobuf/java/core/src/main/java/com/google/protobuf/RopeByteString.java

 // Protocol Buffers - Google's data interchange format
 // Copyright 2008 Google Inc.  All rights reserved.
 // https://developers.google.com/protocol-buffers/
 //
 // 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.
@@ skipping 388 matching lines @@
       right.writeToInternal(out, 0, numberToWrite - numberToWriteInLeft);
     }
   }
 
   @Override
   void writeTo(ByteOutput output) throws IOException {
     left.writeTo(output);
     right.writeTo(output);
   }
 
+
   @Override
   protected String toStringInternal(Charset charset) {
     return new String(toByteArray(), charset);
   }
 
   // =================================================================
   // UTF-8 decoding
 
   @Override
   public boolean isValidUtf8() {
@@ skipping 468 matching lines @@
           currentPiece = pieceIterator.next();
           currentPieceSize = currentPiece.size();
         } else {
           currentPiece = null;
           currentPieceSize = 0;
         }
       }
     }
   }
 }