Chrome OS can be said to be considered as one of the final frontiers on where VLC cannot be found, as the media player has existed on Windows, OS X, Linux, BSD, Solaris, OS/2, Haiku/BeOS, and ReactOS for some time already. This was because it was far from a walk in the park for Chrome OS to support VLC, considering it is a native application on all the other platforms where it makes use of low-level APIs in order to output video, audio, and gain access to threads, and was programmed using mainly C and C++. To write VLC in JavaScript as well as other Web technologies which is a requirement by Chrome OS is certainly a monumental ask.
Features of VLC for Chrome OS will include the support for all video files like MKV and DVD ISOs, in addition to audio files such as FLAC and other kinds of audio formats. Subtitles files, ranging from SRT to SSA alongside auto-detection will also be supported as and when possible. Sounds like a winner here, and good job to the VideoLAN team!