Marking this for attention before we push another dev-channel build, since it's extremely disruptive!

let's not block next dev but we need to make sure this is fixed before beta

Albert, could you help finding an owner for this one?

Re #5: I would recommend blocking dev, since this significantly impacts usability and security (windows pop to the front while the user is typing into other windows).

creis, nasko: Might this be related to recent OOPIF/site-isolation changes to i-frame handling?

I've seen this happen on Mac, too.  I don't think there's anything OOPIF related that would affect this, though it's possible.  Can someone bisect it?

Unfortunately I am not able to repro in Mac in latest Dev - 54.0.2840.14. Song can you give a try in CrOS?

Reproducible in Chrome 54.0.2840.13/CrOS 8743.13 - Candy
Not reproducible in Chrome 53.0.2785.100/CrOS 8530.80.0 - paine

Verified the issue on Mac 10.11.6 using chrome dev version #54.0.2840.14, reported version #54.0.2830.0 and latest canary #55.0.2853.0. 
Observed that the issue is not reproducible.

Attaching screencast for the same.

malaykeshav@ - Could you please verify the screencast and let us know if this is need to be done.

Thanks,

Deleted: 639943.mp4 4.0 MB

	639943.mp4 4.0 MB View Download

As per #14 not a blocker for desktop.

#14 - I am not sure if thats the right way to repro this issue on MAC.
@creis (#9) could you give the steps on how it can be done?

I'll see if I can repro it reliably on Mac.  For now, let's treat this bug as ChromeOS specific until I can confirm otherwise.

Checked the issue on both latest dev[55.0.2852.0/8784.0.0 gnawty] and Stable build [52.0.2743.85/8350.60.0 daisy]

Steps used are: Signed in >> Opened 6-10 windows >> Signed out >> Signed in again >> While typing in one of the window remaining windows pops up and focus lost from window which we are using[typing].

Issue is seen in M52 52.0.2743.85/8350.60.0 daisy stable too.

Comments 14-17: I tried again on my Mac and couldn't repro in 55.0.2853.0.  I definitely saw it in a previous Mac Dev channel version, but maybe that was fixed.  Sorry for the noise.

I'm able to reproduce the issue on Mac 10.11/ Chrome 54.0.2840.16

Steps :
1. open chrome://settings and enable "Continue where you left off"
2. open few tabs, and navigate to maps.google.com, cnn.com, youtube.com, gmail.com on each tabs.   Focus on cnn.com tab
3. open new window and navigate to google.com/translate
4. close the Chrome browser from Mac system menu
5. reopen the Chrome browser
6. try to enter on google.com/translate while loading the cnn.com, youtube.com... pages 

Then, google.com/translate lost focus.  cnn.com becomes active window.

I'm pretty sure this is the same as 634248. But passing to Erik to make that call.

Yes, that would explain why it repros in 54.0.2840.16 (before erikchen's r415472) and not in 55.0.2853.0 (after it).

erikchen@: Can your fix be merged to M54?

C#18, and https://bugs.chromium.org/p/chromium/issues/detail?id=634248#c15, both imply that there may be remaining issues. Note that this issue has been present for many, many years, but has recently had a spike in activity, presumably because of changes caused by OOPIF. 

I can merge my change, but given that there are remaining issues, perhaps someone from the site-isolation team should continue to investigate? This may be a release blocker for OOPIF :(

Comment 24: This almost certainly cannot be because of OOPIFs.  This bug was filed for ChromeOS behavior on August 22, and we did not start a Finch trial of OOPIFs on ChromeOS until August 31.

I'm not aware of any OOPIF connection here other than wez's speculation in comment 8, and I think that was just a guess.  Have you seen any other evidence that OOPIFs are involved?

The problem [that I fixed] was related to the timing of callbacks from RenderFrameImpl::OpenURL, which made me think of OOPIF, though I'd be happy to be proven wrong. 

Maybe you can look at https://bugs.chromium.org/p/chromium/issues/detail?id=634248#c7 and will better know what caused this bug to start triggering recently?

This is bothering the heck out of me on Chrome OS 54.0.2840.13. I have two fullscreen windows and if I alt-tab during session restor focus will repeatedly switch to the other window.

I just checked for updates (dev channel) and one is available. Will report back once it loads.

Still happens on Chrome OS 54.0.2840.24 but I guess that is expected since the hopeful fix has not been verified and merged. I will try to test on ToT later today.

Song, can you try a repro in latest canary.

Not reproduce the issue on Chrome 55.0.2873.4-canary/Mac 10.11.6

Friendly ping, this a stable blocker for M54, please try to have a fix in by the first week of October so it can be fixed in time for the release.

As per #29 nor reproducible in Mac.

This still repros in 55.0.2842.0.  Erik, are you investigating?

No, I'm not. 

sky@, can you find a new owner, plz? Pretty urgent to get this resolved, given the impact of the regression and that M54 Stable is only a few weeks off.

Dupe of  bug 634248 ?

Hi wez@, can tot reproduce this on chromeos? I am still trying to get a repo. If tot can, I then don't need to go to M54.

Re #38: This issue still repros on 55.0.2842.0 so it seems likely to still affect ToT.

I am unable to repro this on 55.0.2880.0, FWIW.

Re comment 40, same here, I can only reproduce it consistently on device with m54 chrome. Never has a repo on tot chrome.

warx@ is looking into this, reassigning.

Hi wez@, can you please verifiy if the issue can happen after 54.0.2840.47. I didn't see it happen from my test. Thanks!

Re #44: All of my devices are on M55.x at this point, sorry! As noted in #40, none of them repro this issue any more.