[libfuzzer] proto-based renderer fuzzer draft

third_party/protobuf/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 config("protobuf_config") {
   include_dirs = [ "src" ]
   defines = [
     "GOOGLE_PROTOBUF_NO_RTTI",
     "GOOGLE_PROTOBUF_NO_STATIC_INITIALIZER",
   ]
@@ skipping 159 matching lines @@
     public_configs += [ ":protobuf_use_dlls" ]
     defines = [ "LIBPROTOBUF_EXPORTS" ]
   }
 }
 
 # This is the full, heavy protobuf lib that's needed for c++ .protos that don't
 # specify the LITE_RUNTIME option. The protocol compiler itself (protoc) falls
 # into that category. Do not use in Chrome code.
 static_library("protobuf_full") {
   # Prevent people from depending on this outside our file.
-  visibility = [ ":*" ]
+  visibility = [
+    ":*",
+    # requires descriptors & reflection; testonly.
+    "//third_party/libprotobuf-mutator:*",
+  ]
 
   sources = protobuf_lite_sources
   sources += [
     "src/google/protobuf/any.cc",
     "src/google/protobuf/any.h",
     "src/google/protobuf/any.pb.cc",
     "src/google/protobuf/any.pb.h",
     "src/google/protobuf/api.pb.cc",
     "src/google/protobuf/api.pb.h",
     "src/google/protobuf/compiler/importer.cc",
@@ skipping 452 matching lines @@
     ":copy_google_protobuf_internal",
     ":copy_six",
   ]
 
   # Targets that depend on this should depend on the copied data files.
   data = get_target_outputs(":copy_google")
   data += get_target_outputs(":copy_six")
   data += get_target_outputs(":copy_google_protobuf")
   data += get_target_outputs(":copy_google_protobuf_internal")
 }