https://hg.mozilla.org/mozilla-central/file/0ba72e8027cfcbcbf3426770ac264a7ade2af090/dom/media/MediaDecoderReader.cpp#l166 The reader queue calls ReleaseMediaResources() to suspend a reader. https://hg.mozilla.org/mozilla-central/file/0ba72e8027cfcbcbf3426770ac264a7ade2af090/dom/media/MediaDecoderReader.h#l105 It says ReadMetadata() needs to be called in order to recover a reader. Therefore, MDSM should enter dormant state when its reader is suspended and exit dormant (which will then call ReadMetadata()) upon reader resume.

Comment on attachment 8779686 [details] Bug 1292453 - MDSM should enter dormant state when its reader is suspended. https://reviewboard.mozilla.org/r/70636/#review68008 Looks good, as long as we don't break the sequence of releasing the decoders first and then resuming the next reader and restore the seek position on resuming.

Thanks! MDSM's entering/exiting dormant state will not change the suspend status of its reader. However, it is possible to call ReleaseMediaResources() on a resumed reader which is fine. Because we won't crash as long as the number of active decoders is <= the pref value "media.decoder.limit".

Pushed by jwwang@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/f64f8bc8415f MDSM should enter dormant state when its reader is suspended. r=esawin