Bug 833385 - Only update Align if it's changed.
Bug 833385 - Remove unnecessary parentheses.
Bug 833385 - Remove useless const qualifiers.
Bug 833385 - Whitespace.
Bug 833385 - Pref-enable media element additions.
Bug 833385 - Remove webidl forward declaration.

bz says this is wrong.
Bug 833385 - Mark track element attributes pure.