Bug 1315567: P3. Expose flac codec as being available in mp4. r=gerald

MozReview-Commit-ID: 7C6W1KGQ1jE

--HG--
extra : rebase_source : 338dd05c33543f84740fb68da28845154dc27f74

dom/media/fmp4/MP4Decoder.cpp

@@ -141,6 +141,12 @@ MP4Decoder::CanHandleMediaType(const MediaContentType& aType,
             NS_LITERAL_CSTRING("audio/opus"), aType));
         continue;
       }
+      if (codec.EqualsLiteral("flac")) {
+        trackInfos.AppendElement(
+          CreateTrackInfoWithMIMETypeAndContentTypeExtraParameters(
+            NS_LITERAL_CSTRING("audio/flac"), aType));
+        continue;
+      }
       // Note: Only accept H.264 in a video content type, not in an audio
       // content type.
       if (IsWhitelistedH264Codec(codec) && isMP4Video) {