Use -DFUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION for libFuzzer and AFL.

build/config/sanitizers/sanitizers.gni

 # Copyright 2015 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.
 
 import("//build/config/chrome_build.gni")
 import("//build/toolchain/toolchain.gni")
 
 declare_args() {
   # Compile for Address Sanitizer to find memory bugs.
   is_asan = false
@@ skipping 91 matching lines @@
   is_msan = false
   is_syzyasan = false
   is_tsan = false
   is_ubsan = false
   is_ubsan_null = false
   is_ubsan_no_recover = false
   is_ubsan_security = false
   is_ubsan_vptr = false
   msan_track_origins = 0
   sanitizer_coverage_flags = ""
+  use_afl = false
   use_cfi_diag = false
   use_custom_libcxx = false
   use_drfuzz = false
   use_libfuzzer = false
   use_prebuilt_instrumented_libraries = false
   use_locally_built_instrumented_libraries = false
   use_sanitizer_coverage = false
 }
 
 # Args that are in turn dependent on other args must be in a separate
@@ skipping 60 matching lines @@
 assert(!is_debug || !(is_msan || is_ubsan || is_ubsan_null || is_ubsan_vptr),
        "Sanitizers should generally be used in release (set is_debug=false).")
 
 assert(!is_msan || (is_linux && current_cpu == "x64"),
        "MSan currently only works on 64-bit Linux and ChromeOS builds.")
 
 # ASAN build on Windows is not working in debug mode. Intercepting memory
 # allocation functions is hard on Windows and not yet implemented in LLVM.
 assert(!is_win || !is_debug || !is_asan,
        "ASan on Windows doesn't work in debug (set is_debug=false).")