I can not reproduce it. Does it happen on every site, where the Translation Bar appears?

Yes, for me it happens on every site (e.g. https://wikipedia.de/), until I press the x to close the Translation Bar or until it goes away by itself. When this reproduces, both the renderer process and the browser process consume a lot of CPU. Once the Translation Bar is closed, the CPU usage returns back to normal.

alex.dima@: Thanks for your feedback. Can you please grab a sample in the Activity.app of the hanging process and attach it here? Thanks in advance.

Here it is

Deleted: Sample of Google Chrome Helper.txt 235 KB

Sample of Google Chrome Helper.txt 235 KB View Download

Thanks for the attachment.

rsesek@: Maybe you can take a look at the Sample file? Thank you :-)

Unable to reproduce the issue on reported chrome version 64.0.3282.186 using Mac 10.13.1 with the below mentioned steps.
1. Launched Chrome
2. Navigated to https://wikipedia.de/
3. Clicked on Translate
We didn't observe any 100% CPU usage of the tab opened. Attaching the screen cast of the same.

@Reporter: Could you please have a look at the screen cast and let us know if we have missed anything in the process of reproducing the issue. Any further inputs from your end may help us.

Thanks! 

Deleted: 820573.mp4 8.4 MB

	820573.mp4 8.4 MB View Download

I also had a bit of a hard time to reproduce after restarting Chrome. It perhaps had something to do with my previous browsing session where I had multiple windows and tabs opened. I tried to recreate that artificially by opening the same static website 30 times. But in my previous browsing session, I probably opened and closed hundreds of tabs over the course of multiple days.

It is not as drastic as before, perhaps it takes ~3 days of browsing for it to fully reproduce, but the 3 renderer processes that show the translation bar are consuming IMHO unexpected high amounts of CPU when not visible.

It is ok with me if you wanna close as cannot reproduce, I can pay more attention to figure out what usage pattern brought me in that state.

Deleted: Kapture 2018-03-12 at 11.06.32.mp4 2.6 MB

	Kapture 2018-03-12 at 11.06.32.mp4 2.6 MB View Download

It also doesn't help that after recording the screencast Chrome just updated itself to Version 65.0.3325.146.

I can update this issue if I can reproduce again, please close if you cannot reproduce.

Thanks for your time1

Thank you for providing more feedback. Adding the requester to the cc list.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

Looks like a decent chunk of time is spent in ui::AXTreeSerializer.

Deleted: bug-820573.txt 324 KB

bug-820573.txt 324 KB View Download

Unable to reproduce the issue on MacBook Air 10.13.3 and MacBook Pro 10.13.3.
As per comment#9 and #10 by reporter, where the issue is not consistently reproducible from his end, Closing this issue.
Removing Needs-Bisect label.

Please feel free to raise a new issue, if the issue is consistently seen.

Thanks!