| Index: Source/core/html/track/TextTrack.cpp | 
| diff --git a/Source/core/html/track/TextTrack.cpp b/Source/core/html/track/TextTrack.cpp | 
| index b95a35dbef448af17805b09669f465e226735144..67c9d5a1b8c286125d0f7e2afe232ab21730a112 100644 | 
| --- a/Source/core/html/track/TextTrack.cpp | 
| +++ b/Source/core/html/track/TextTrack.cpp | 
| @@ -141,6 +141,22 @@ bool TextTrack::isValidKindKeyword(const AtomicString& value) | 
| return false; | 
| } | 
|  | 
| +bool TextTrack::isValidKindKeyword(const String& value) | 
| +{ | 
| +    if (value == subtitlesKeyword()) | 
| +        return true; | 
| +    if (value == captionsKeyword()) | 
| +        return true; | 
| +    if (value == descriptionsKeyword()) | 
| +        return true; | 
| +    if (value == chaptersKeyword()) | 
| +        return true; | 
| +    if (value == metadataKeyword()) | 
| +        return true; | 
| + | 
| +    return false; | 
| +} | 
| + | 
| void TextTrack::setTrackList(TextTrackList* trackList) | 
| { | 
| if (!trackList && mediaElement() && m_cues) | 
|  |