584570 - Pages containing html 5 media elements won't enter bfcache

Status: RESOLVED INACTIVE

(Core :: Audio/Video: Playback, defect)

Description

[cajbir (:cajbir)]

If a page contains an HTML 5 video element that is in a load group and is loading then it won't go into bfcache. This can be demonstrated by:

1) Visit http://www.double.co.nz/video_test/simple.html
2) Before video fully loads navigate to another page
3) Hit back button

Expected result:

Page containing video is restored from bfcache with video resuming where it left off when it was navigated away from

Actual result:

Page is reconstructed and video is started from the beginning

The code that prevents it from going into bfcache is in nsDocument::CanSavePresentation where it checks for request in the load group.

Comment 1

[Boris Zbarsky [:bzbarsky]]

Right; the point is that in general we can't "restore" a state where a network request is in mid-load.  If for video we can in fact do this, then we'd need to adjust things as follows:

1)  Flag the video requests as being magic in the relevant way.
2)  Ignore "magic" requests when doing CanSavePresentation.
3)  Make sure to stop the video requests when going into bfcache and restart them
    when coming out of bfcache.

Comment 2

[Nils Ohlmeier [:drno]]

Mass closing do to inactivity.
Feel free to re-open if still needed.