Update third_party/protobuf to protobuf-v3.0.0-beta-3

third_party/protobuf/conformance/conformance_objc.m

 // Protocol Buffers - Google's data interchange format
 // Copyright 2015 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 77 matching lines @@
   if (testMessage) {
     switch (request.requestedOutputFormat) {
       case WireFormat_GPBUnrecognizedEnumeratorValue:
       case WireFormat_Unspecified:
         Die(@"Unrecognized/unspecified output format: %@", request);
         break;
 
       case WireFormat_Protobuf:
         response.protobufPayload = testMessage.data;
         if (!response.protobufPayload) {
-          response.runtimeError =
+          response.serializeError =
             [NSString stringWithFormat:@"Failed to make data from: %@", testMessage];
         }
         break;
 
       case WireFormat_Json:
         response.skipped = @"ObjC doesn't support generating JSON";
         break;
     }
   }
 
@@ skipping 61 matching lines @@
     while (notDone) {
       @autoreleasepool {
         notDone = DoTestIo(input, output);
       }
     }
 
     NSLog(@"Received EOF from test runner after %d tests, exiting.", testCount);
   }
   return 0;
 }