This upstream change provides protoc support for this feature:
https://github.com/protocolbuffers/protobuf/commit/375d32d3eb5d91c10542ebc13252f95249e67714
1) This change needs to be present on Chrome OS
a) protobuf needs to be upreved to 3.6.1
b) afterward it can be upreved to either HEAD or the tag that comes after 3.6.1
2) There needs to be a way of using this feature when building protobufs for fuzz targets that use libprotobuf-mutator.
Comment 1 by allenwebb@google.com
, Nov 15