Convert USE_PROPRIETARY_CODECS to a buildflag header.

media/base/eme_constants.h

Index: media/base/eme_constants.h
diff --git a/media/base/eme_constants.h b/media/base/eme_constants.h
index acf1d6eafd05f2e642d7bc01d4f2410f75796452..7a7d933b74b2c7d839505bc1ab8ce5932ac0694a 100644
--- a/media/base/eme_constants.h
+++ b/media/base/eme_constants.h
@@ -30,7 +30,7 @@ enum EmeCodec {
   EME_CODEC_WEBM_VP9 = 1 << 3,
   EME_CODEC_WEBM_VIDEO_ALL = (EME_CODEC_WEBM_VP8 | EME_CODEC_WEBM_VP9),
   EME_CODEC_WEBM_ALL = (EME_CODEC_WEBM_AUDIO_ALL | EME_CODEC_WEBM_VIDEO_ALL),
-#if defined(USE_PROPRIETARY_CODECS)
+#if BUILDFLAG(USE_PROPRIETARY_CODECS)
   EME_CODEC_MP4_AAC = 1 << 4,
   EME_CODEC_MP4_AUDIO_ALL = EME_CODEC_MP4_AAC,
   EME_CODEC_MP4_AVC1 = 1 << 5,
@@ -50,7 +50,7 @@ enum EmeCodec {
   EME_CODEC_AUDIO_ALL = EME_CODEC_WEBM_AUDIO_ALL,
   EME_CODEC_VIDEO_ALL = EME_CODEC_WEBM_VIDEO_ALL,
   EME_CODEC_ALL = EME_CODEC_WEBM_ALL,
-#endif  // defined(USE_PROPRIETARY_CODECS)
+#endif  // BUILDFLAG(USE_PROPRIETARY_CODECS)
 };
 
 typedef uint32_t SupportedCodecs;