Add FLAC audio codec support

media/base/mime_util_internal.cc

Index: media/base/mime_util_internal.cc
diff --git a/media/base/mime_util_internal.cc b/media/base/mime_util_internal.cc
index 11a763e74ab3c0054e6a39db8a3bcdbac462b19b..70faa9c6043a1e0d61c269279e94425a712937e8 100644
--- a/media/base/mime_util_internal.cc
+++ b/media/base/mime_util_internal.cc
@@ -33,6 +33,7 @@ struct CodecIDMappings {
 // The "mp4a" strings come from RFC 6381.
 static const CodecIDMappings kUnambiguousCodecStringMap[] = {
     {"1", MimeUtil::PCM},  // We only allow this for WAV so it isn't ambiguous.
+    {"flac", MimeUtil::FLAC},
     // avc1/avc3.XXXXXX may be unambiguous; handled by ParseAVCCodecId().
     // hev1/hvc1.XXXXXX may be unambiguous; handled by ParseHEVCCodecID().
     // vp9, vp9.0, vp09.xx.xx.xx.xx.xx.xx.xx may be unambiguous; handled by
@@ -366,6 +367,9 @@ void MimeUtil::AddSupportedMediaFormats() {
   CodecSet webm_codecs(webm_audio_codecs);
   webm_codecs.insert(webm_video_codecs.begin(), webm_video_codecs.end());
 
+  CodecSet flac_audio_codecs;
+  flac_audio_codecs.insert(FLAC);
+
 #if defined(USE_PROPRIETARY_CODECS)
   CodecSet mp3_codecs;
   mp3_codecs.insert(MP3);
@@ -409,6 +413,10 @@ void MimeUtil::AddSupportedMediaFormats() {
   // TODO(ddorwin): Should the application type support Opus?
   AddContainerWithCodecs("application/ogg", ogg_codecs, false);
 
+  AddContainerWithCodecs("audio/flac", flac_audio_codecs, false);
+  AddContainerWithCodecs("audio/x-flac", flac_audio_codecs, false);
+  AddContainerWithCodecs("application/x-flac", flac_audio_codecs, false);

[servolk, 2016/09/23 22:17:15]

Firefox supports all 3 mime types
(https://reviewboard.mozilla.org/r/72408/diff/1/?file=2074198#file2074198), so
I've also added all 3 for now.

+
 #if defined(USE_PROPRIETARY_CODECS)
   AddContainerWithCodecs("audio/mpeg", mp3_codecs, true);  // Allow "mp3".
   AddContainerWithCodecs("audio/mp3", implicit_codec, true);
@@ -562,6 +570,7 @@ bool MimeUtil::IsCodecSupportedOnPlatform(
     // The remaining codecs may be supported depending on platform abilities.
     // ----------------------------------------------------------------------
 
+    case FLAC:
     case PCM:
     case MP3:
     case MPEG4_AAC:
@@ -766,6 +775,7 @@ bool MimeUtil::IsCodecProprietary(Codec codec) const {
     case HEVC:
       return true;
 
+    case FLAC:
     case PCM:
     case VORBIS:
     case OPUS: