mw.MwEmbedSupport.js has a large number of methods directly on the mw object.
Several of these are general-sounding (mw.ready, mw.load, mw.inherit), so they can be initially confused with core methods. Others are specific to MwEmbedSupport (e.g. getEmbedPlayerPath), but just shouldn't be on the main object.
I think these should be moved to mw.mwEmbedSupport or somewhere else appropriate.