The "fastSeek()" method was added to the WhatWG spec in r7437 [1], based on bug 14851. I doubt that all ports are able to do "approximate seeking" so this will have to be an opt-in feature. [1] http://html5.org/tools/web-apps-tracker?from=7438&to=7439 [2] https://www.w3.org/Bugs/Public/show_bug.cgi?id=14851.
<rdar://problem/13390190>
This was done or bug 124262. *** This bug has been marked as a duplicate of bug 124262 ***