Section 4.3. Addition to Media Element Load Algorithm [1] has a single purpose: "Clear the keys attribute for this media element." This is left over from the original spec [2], which said to "Clear all cached keys for this media element." At that time, it was important to be able to reset the key state of the media element. However, now, the state can be reset by removing/replacing the attached MediaKeys.

Therefore, I think we should remove this section. This simplifies things (no longer modifying an external algorithm) and gives applications more flexibility (the src attribute can be changed without having to call setMediaKeys() each time.

[1] https://dvcs.w3.org/hg/html-media/raw-file/default/encrypted-media/encrypted-media.html#algorithms-load
[2] https://dvcs.w3.org/hg/html-media/raw-file/eme-v0.1b/encrypted-media/encrypted-media.html#algorithms-load