1443315 - Ensure preloaded about:newtab always has layers ready to avoid white flash when opening new tabs

Status: RESOLVED FIXED

(Firefox :: Tabbed Browser, enhancement, P3)

Description

[Mike Conley (:mconley) (:⚙️)]

This is similar to bug 1389546, but can be made simpler now that we have renderLayers separated from docShellIsActive.

Essentially, for preloaded about:newtab's, I think we can have their layers always being rendered in the background, and this should allow us to avoid the annoying white flash we see when opening new tabs.

Comment 1

[Mike Conley (:mconley) (:⚙️)]

Attachment: Bug 1443315 - Make preloaded about:newtab's layers always rendered so that we avoid the flash when opening new tabs.

Review commit: https://reviewboard.mozilla.org/r/225148/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/225148/

Comment 2

[Florian Quèze [:florian]]

Comment on attachment 8956239 [details]
Bug 1443315 - Make preloaded about:newtab's layers always rendered so that we avoid the flash when opening new tabs.

https://reviewboard.mozilla.org/r/225148/#review231122

Seems reasonable, but I wonder how we can verify that this has the intended effect. Do you have steps to reproduce for this specific white flash? Is this something we should verify on a video recording on the ref hardware? Can we have flicker tests for it?

Comment 3

[Mike Conley (:mconley) (:⚙️)]

Attachment: Bug 1443315 - Don't set docShellIsActive to false for preloaded browsers that are being inserted.

Review commit: https://reviewboard.mozilla.org/r/225530/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/225530/

Comment 4

[Mike Conley (:mconley) (:⚙️)]

Comment on attachment 8956239 [details]
Bug 1443315 - Make preloaded about:newtab's layers always rendered so that we avoid the flash when opening new tabs.

Review request updated; see interdiff: https://reviewboard.mozilla.org/r/225148/diff/1-2/

Comment 5

[Dão Gottwald [:dao]]

Comment on attachment 8956239 [details]
Bug 1443315 - Make preloaded about:newtab's layers always rendered so that we avoid the flash when opening new tabs.

https://reviewboard.mozilla.org/r/225148/#review231592

::: browser/base/content/tabbrowser.js:1816
(Diff revision 2)
>      }
>  
>      browser.loadURI(BROWSER_NEW_TAB_URL);
>      browser.docShellIsActive = false;
> +    browser.renderLayers = true;
> +    browser._urlbarFocused = true;

Why is this needed and what does this have to do with this bug?

Comment 6

[Dão Gottwald [:dao]]

Comment on attachment 8956602 [details]
Bug 1443315 - Don't set docShellIsActive to false for preloaded browsers that are being inserted.

https://reviewboard.mozilla.org/r/225530/#review231594

Comment 7

[Mike Conley (:mconley) (:⚙️)]

Comment on attachment 8956239 [details]
Bug 1443315 - Make preloaded about:newtab's layers always rendered so that we avoid the flash when opening new tabs.

https://reviewboard.mozilla.org/r/225148/#review231592

> Why is this needed and what does this have to do with this bug?

This is needed to avoid a test failure where the URL bar isn't focused in time by the time the tab switch completes.

Comment 8

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/416654775d77
Make preloaded about:newtab's layers always rendered so that we avoid the flash when opening new tabs. r=florian
https://hg.mozilla.org/integration/autoland/rev/c5bcdb85fb8d
Don't set docShellIsActive to false for preloaded browsers that are being inserted. r=dao

Comment 9

[Stefan Hindli [:stefan_hindli]]

https://hg.mozilla.org/mozilla-central/rev/416654775d77
https://hg.mozilla.org/mozilla-central/rev/c5bcdb85fb8d