third_party/protobuf: Update to HEAD (f52e188fe4)

third_party/protobuf/src/google/protobuf/util/internal/object_writer.h

 // 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 83 matching lines @@
 
   // Renders a StringPiece value. This is for rendering strings.
   virtual ObjectWriter* RenderString(StringPiece name, StringPiece value) = 0;
 
   // Renders a bytes value.
   virtual ObjectWriter* RenderBytes(StringPiece name, StringPiece value) = 0;
 
   // Renders a Null value.
   virtual ObjectWriter* RenderNull(StringPiece name) = 0;
 
+
   // Renders a DataPiece object to a ObjectWriter.
   static void RenderDataPieceTo(const DataPiece& data, StringPiece name,
                                 ObjectWriter* ow);
 
   // Indicates whether this ObjectWriter has completed writing the root message,
   // usually this means writing of one complete object. Subclasses must override
   // this behavior appropriately.
   virtual bool done() { return false; }
 
   void set_use_strict_base64_decoding(bool value) {
     use_strict_base64_decoding_ = value;
   }
 
   bool use_strict_base64_decoding() const {
     return use_strict_base64_decoding_;
   }
 
+  // Whether empty strings should be rendered for the next name for Start/Render
+  // calls. This setting is only valid until the next key is rendered, after
+  // which it gets reset.
+  // It is up to the derived classes to interpret this and render accordingly.
+  // Default implementation ignores this setting.
+  virtual void empty_name_ok_for_next_key() {}
+
  protected:
   ObjectWriter() : use_strict_base64_decoding_(true) {}
 
  private:
   // If set to true, we use the stricter version of base64 decoding for byte
   // fields by making sure decoded version encodes back to the original string.
   bool use_strict_base64_decoding_;
 
   // Do not add any data members to this class.
   GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(ObjectWriter);
 };
 
 }  // namespace converter
 }  // namespace util
 }  // namespace protobuf
 
 }  // namespace google
 #endif  // GOOGLE_PROTOBUF_UTIL_CONVERTER_OBJECT_WRITER_H__