Revert "third_party/protobuf: Update to HEAD (83d681ee2c)"

third_party/protobuf/src/google/protobuf/struct.proto

 // 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 15 matching lines @@
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 syntax = "proto3";
 
 package google.protobuf;
 
 option csharp_namespace = "Google.Protobuf.WellKnownTypes";
-option cc_enable_arenas = true;
 option go_package = "github.com/golang/protobuf/ptypes/struct;structpb";
 option java_package = "com.google.protobuf";
 option java_outer_classname = "StructProto";
 option java_multiple_files = true;
+option java_generate_equals_and_hash = true;
 option objc_class_prefix = "GPB";
 
 
 // `Struct` represents a structured data value, consisting of fields
 // which map to dynamically typed values. In some languages, `Struct`
 // might be supported by a native representation. For example, in
 // scripting languages like JS a struct is represented as an
 // object. The details of that representation are described together
 // with the proto support for the language.
 //
@@ skipping 36 matching lines @@
   NULL_VALUE = 0;
 }
 
 // `ListValue` is a wrapper around a repeated field of values.
 //
 // The JSON representation for `ListValue` is JSON array.
 message ListValue {
   // Repeated field of dynamically typed values.
   repeated Value values = 1;
 }