Alice0775 White Reporter
	Description • 9 years ago

Steps to reproduce:
1. set nglayout.debug.paint_flashing = true
2. Open data:text/html;charset=utf-8,<video autoplay="autoplay" controls="" loop="loop" preload="none" height="350" width="610"><source src="https://videos.cdn.mozilla.net/uploads/mozillaorg/Firefox_global_final.webm" type="video/webm"></video>
3. Wait until become looping
   --- Observe, unnecessary screen paint/refresh starts
4. Pause video
   --- Observe, unnecessary screen paint/refresh continued

Actual Results:
Unnecessary screen paint/refresh starts when the video loops to playback
Screen paints/refreshes continuously even if the video is pausing

Expected Results:
nnecessary screen paint/refresh should not start.
Screen should stop paint/refreshe, because the video is pausing.

	Alice0775 White Reporter
	Comment 2 • 9 years ago

Actually, it is not necessary the loop attribute. 
Moving seekbar causes the screen unnecessary paint/refresh.

	Ralph Giles (:rillian)
	Comment 3 • 9 years ago

Is there a way to tell where in the stack this is happening, and how expensive the spurious repaints are?

	Anthony Jones (:ajones, :kentuckyfriedtakahe, :k17e)
	Comment 4 • 9 years ago

Robert - is this a compositor issue?

	Robert O'Callahan (:roc) (email my personal email if necessary)
	Comment 5 • 9 years ago

No. This is pretty clearly a layout bug involving the spinner causing unnecessary invalidation. Looking into it.

	Robert O'Callahan (:roc) (email my personal email if necessary)
	Comment 6 • 9 years ago

https://dxr.mozilla.org/mozilla-central/source/toolkit/content/widgets/videocontrols.xml
https://dxr.mozilla.org/mozilla-central/source/toolkit/themes/windows/global/media/videocontrols.css

After seeking we get into a state where the statusIcon element has type="throbber", so it gets the animated throbber image. Its statusOverlay parent has the fadeOut attribute set, so is opacity 0, which is why you can't see the throbber.

Arguably, after the fade-out transition has finished the videocontrols themselves should remove the throbber state so we're not continuously animating the image. However, it's best if we automatically avoid repainting for animated content inside an opacity:0 element. I think DLBI should already be doing that so I need to figure why that's not working.

	Robert O'Callahan (:roc) (email my personal email if necessary)
	Comment 7 • 9 years ago

Bug 1213582. Skip display items in ProcessDisplayItems if we only need items for event regions, and this item isn't one and doesn't have descendants. r=mattwoodrow

	Robert O'Callahan (:roc) (email my personal email if necessary)
	Comment 8 • 9 years ago

Bug 1213582. Don't flatten away opacity:0 containers. r=mattwoodrow

	Matt Woodrow (:mattwoodrow)
	Comment 9 • 9 years ago

Comment on attachment 8685749 [details]
MozReview Request: Bug 1213582. Skip display items in ProcessDisplayItems if we only need items for event regions, and this item isn't one and doesn't have descendants. r=mattwoodrow

https://reviewboard.mozilla.org/r/24879/#review22413

	Matt Woodrow (:mattwoodrow)
	Comment 10 • 9 years ago

Comment on attachment 8685750 [details]
MozReview Request: Bug 1213582. Don't flatten away opacity:0 containers. r=mattwoodrow

https://reviewboard.mozilla.org/r/24881/#review22415

	Robert O'Callahan (:roc) (email my personal email if necessary)
	Comment 11 • 9 years ago

https://treeherder.mozilla.org/#/jobs?repo=try&revision=2d9327a71604

	Robert O'Callahan (:roc) (email my personal email if necessary)
	Comment 12 • 9 years ago

https://hg.mozilla.org/integration/mozilla-inbound/rev/c1935f0c639b3c52a0046d1eab7888fbda65325a
Bug 1213582. Skip display items in ProcessDisplayItems if we only need items for event regions, and this item isn't one and doesn't have descendants. r=mattwoodrow

https://hg.mozilla.org/integration/mozilla-inbound/rev/55a30946c6fba7e287099f956065df7508ab1a8a
Bug 1213582. Don't flatten away opacity:0 containers. r=mattwoodrow

	Carsten Book [:Tomcat]
	Comment 13 • 9 years ago
bugherder

https://hg.mozilla.org/mozilla-central/rev/c1935f0c639b
https://hg.mozilla.org/mozilla-central/rev/55a30946c6fb