Reverts third_party/protobuf: Update to HEAD (f52e188fe4)

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

Index: third_party/protobuf/src/google/protobuf/util/internal/object_writer.h
diff --git a/third_party/protobuf/src/google/protobuf/util/internal/object_writer.h b/third_party/protobuf/src/google/protobuf/util/internal/object_writer.h
index b6fbd19bf7140d707913775de601c6597863ea65..9f07363d89e52142d2afb5e1c1de1ec4a46a8e11 100644
--- a/third_party/protobuf/src/google/protobuf/util/internal/object_writer.h
+++ b/third_party/protobuf/src/google/protobuf/util/internal/object_writer.h
@@ -101,7 +101,6 @@ class LIBPROTOBUF_EXPORT ObjectWriter {
   // 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);
@@ -119,13 +118,6 @@ class LIBPROTOBUF_EXPORT ObjectWriter {
     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) {}