Convert USE_PROPRIETARY_CODECS to a buildflag header.

third_party/widevine/cdm/widevine_cdm_common.h

Index: third_party/widevine/cdm/widevine_cdm_common.h
diff --git a/third_party/widevine/cdm/widevine_cdm_common.h b/third_party/widevine/cdm/widevine_cdm_common.h
index 1a962a01160a4e69c6fce16113868cc54fda84e7..f411b9d6e97df4d8914b6f7b65968dabaf064fbc 100644
--- a/third_party/widevine/cdm/widevine_cdm_common.h
+++ b/third_party/widevine/cdm/widevine_cdm_common.h
@@ -5,6 +5,7 @@
 #ifndef WIDEVINE_CDM_WIDEVINE_CDM_COMMON_H_
 #define WIDEVINE_CDM_WIDEVINE_CDM_COMMON_H_
 
+#include "media/media_features.h"
 #include "ppapi/features/features.h"
 
 // This file defines constants common to all Widevine CDM versions.
@@ -54,9 +55,9 @@ const char kCdmSupportedCodecsParamName[] = "codecs";
 const char kCdmSupportedCodecsValueDelimiter = ',';
 const char kCdmSupportedCodecVp8[] = "vp8";
 const char kCdmSupportedCodecVp9[] = "vp9.0";
-#if defined(USE_PROPRIETARY_CODECS)
+#if BUILDFLAG(USE_PROPRIETARY_CODECS)
 const char kCdmSupportedCodecAvc1[] = "avc1";
-#endif  // defined(USE_PROPRIETARY_CODECS)
+#endif  // BUILDFLAG(USE_PROPRIETARY_CODECS)
 
 #if defined(OS_MACOSX) || defined(OS_WIN)
 // CDM is installed by the component installer instead of the Chrome installer.