Allow blur of embedded objects (e.g. flash).

[smblott-github]

Fixes #844.
Fixes #1193.

The is a refactor of #844.

@mrmr1993: There's a slight change to the logic. Does it look OK to you?

Tested on BBC iPlayer.

Edit: #1093 -> #1193.

[mrmr1993]

This works perfectly for me, logic seems consistent with before. Merge away! :)

[smblott-github]

I've reverted this merge with: a277fa6.

On reflection, it just seems too risky. It works for your use case, @mrmr1993, but I think there are other use cases where it's undesirable.

[mrmr1993]

@smblott-github, can you say what those use cases are?

The 'risky' thing is assuming we should handle <esc> everywhere before the page can do so. As I've said before, this change just stops us from capturing the key and then effectively performing a no-op in certain situations, which was a worst-of-all-worlds situation.

[smblott-github]

Here's the scenario I have in mind.

There's a flash game which uses keyboard shortcuts, and ? to show the game's keyboard-shortcuts help page, and esc to return to the game. If we capture the esc, then there might be no way for the player of the game to ever get out of the help page. And if we blur flash, then we've changed the users experience.

I don't have a concrete example. But the risk/benefit doesn't seem acceptable. So sticking with the status quo, even if it doesn't satisfy your use case, seems like the best option.