Raise gyp/GN failure if proprietary_codecs=1 and ffmpeg_branding=Chromium

media/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.
 
 import("//build/buildflag_header.gni")
 import("//build/config/android/config.gni")
 import("//build/config/arm.gni")
 import("//build/config/features.gni")
 import("//build/config/linux/pkg_config.gni")
 import("//build/config/ui.gni")
 import("//media/media_options.gni")
 import("//testing/libfuzzer/fuzzer_test.gni")
 import("//testing/test.gni")
+import("//third_party/ffmpeg/ffmpeg_options.gni")
 
 buildflag_header("media_features") {
   header = "media_features.h"
 
   flags = [
     "ENABLE_AC3_EAC3_AUDIO_DEMUXING=$enable_ac3_eac3_audio_demuxing",
     "ENABLE_HEVC_DEMUXING=$enable_hevc_demuxing",
     "ENABLE_MSE_MPEG2TS_STREAM_PARSER=$enable_mse_mpeg2ts_stream_parser",
   ]
 }
 
+if (proprietary_codecs && media_use_ffmpeg) {
+  assert(
+      ffmpeg_branding != "Chromium",
+      "proprietary codecs and ffmpeg_branding set to Chromium are incompatible")
+}
+
 # Common configuration for targets in the media directory.
 # NOT for exporting.
 config("media_config") {
   defines = []
   if (!media_use_libvpx) {
     defines += [ "MEDIA_DISABLE_LIBVPX" ]
   }
   if (!media_use_ffmpeg) {
     defines += [ "MEDIA_DISABLE_FFMPEG" ]
   }
@@ skipping 842 matching lines @@
   sources = [
     "filters/vpx_video_decoder_fuzzertest.cc",
   ]
   deps = [
     ":media",
     "//base",
   ]
   libfuzzer_options = [ "max_len = 400000" ]
   seed_corpus = "//media/test/data"
 }