1749286 - remove redundant calls marking remote browsers as hidden

Status: RESOLVED FIXED

(Core :: Web Painting, task)

Comment 1

[Timothy Nikkel (:tnikkel)]

Attachment: Bug 1749286. Remove redundant calls marking remote browsers as hidden. r?miko

Remote browsers are fully hidden by default. The only place we mark them as visible is in nsDisplayRemote::CreateWebRenderCommands

https://searchfox.org/mozilla-central/rev/b3933df6e119bd6caf5d9e5868670348ec26dee3/layout/generic/nsSubDocumentFrame.cpp#1363

and we create a WebRenderUserData item there that marks the remote browser hidden in its destructor

https://searchfox.org/mozilla-central/rev/b3933df6e119bd6caf5d9e5868670348ec26dee3/gfx/layers/wr/WebRenderUserData.cpp#426

So that will mark it hidden when it's no longer visible. And in fact we destroy the WebRenderUserData table for the frame at both call sites that we are removing in this patch. So there shouldn't be any change with this patch.

I think the way this redundancy came about was because the code was first added for the layers backend in

https://hg.mozilla.org/integration/mozilla-inbound/rev/b81cf35a573e

and that of course doesn't user WebRenderUserdata so it needed to mark remote browsers hidden in its own way.

And then for webrender in

https://hg.mozilla.org/integration/mozilla-inbound/rev/ac0ad5d8e9a5

And then when FrameLayerBuilder was removed they got put together directly

https://hg.mozilla.org/mozilla-central/rev/a95f6a0cd9eb

The reason this is important is for bug 1737503. In that bug we destroy and recreate a remote iframe to handle a style change. If we mark a remote browser as hidden we will draw it as blank for one frame. So instead we want to delay this until the end of the next frame so we don't do that.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/8d6585a5808d
Remove redundant calls marking remote browsers as hidden. r=miko

Comment 3

[Marian-Vasile Laza]

https://hg.mozilla.org/mozilla-central/rev/8d6585a5808d