If building a fuzzer, define WEBRTC_UNSAFE_FUZZER_MODE.

webrtc/BUILD.gn

 # Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
 #
 # Use of this source code is governed by a BSD-style license
 # that can be found in the LICENSE file in the root of the source
 # tree. An additional intellectual property rights grant can be found
 # in the file PATENTS.  All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
 
 # TODO(kjellander): Rebase this to webrtc/build/common.gypi changes after r6330.
 
@@ skipping 151 matching lines @@
   if (is_android && !is_clang) {
     # The Android NDK doesn"t provide optimized versions of these
     # functions. Ensure they are disabled for all compilers.
     cflags += [
       "-fno-builtin-cos",
       "-fno-builtin-sin",
       "-fno-builtin-cosf",
       "-fno-builtin-sinf",
     ]
   }
+
+  if (use_libfuzzer || use_drfuzz) {
+    defines += [ "WEBRTC_UNSAFE_FUZZER_MODE" ]

[pbos-webrtc, 2016/05/24 12:54:55]

Add a comment here to say where it's used (and why) since it's not currently in
this codebase but rather chromium.

[katrielc, 2016/05/24 15:30:06]

Done.

+  }
 }
 
 source_set("webrtc") {
   sources = [
     "call.h",
     "config.h",
     "transport.h",
   ]
 
   defines = []
@@ skipping 128 matching lines @@
 if (use_libfuzzer || use_drfuzz) {
   # This target is only here for gn to discover fuzzer build targets under
   # webrtc/test/fuzzers/.
   group("webrtc_fuzzers_dummy") {
     testonly = true
     deps = [
       "test/fuzzers:webrtc_fuzzer_main",
     ]
   }
 }