Open Bug 1531854 Opened 5 years ago Updated 21 days ago

Don't create the hidden window on a normal browsing session


(Firefox :: General, enhancement, P3)




Tracking Status
firefox67 --- affected


(Reporter: Felipe, Unassigned)


(Blocks 1 open bug)


On bug 827976, we lazy-fied the hidden window creation, and moved it to happen after first paint (on _delayedStartup). We want to make it to not be used at all on a normal browsing session, but there's still some remaining work to do, which will be tracked here.

The hidden window will remain supported in the platform, because:

  • it is necessary on macOS
  • we may still allow it to be used on some random features that would be harder to port.
Priority: -- → P3
Depends on: 1527213
Whiteboard: [fxperf] → [fxperf:p3]

Here's a talos comparison with a hacky patch to remove the hidden window from about:home (bug 1527213), this allowing this bug to be fixed (not including some other test failures that need to be figured out):

all numbers in the sessionrestore and startup_about_home_paint go down by some 0.5 - 2.0% margin, except startup_about_home_paint on windows10-64-qr, which goes up for some strange reason.

Severity: normal → S3
Whiteboard: [fxperf:p3]
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