ajdunn83@ Thanks for the issue.

Tested this issue on Mac OS 10.13.3 and Windows 10 on the latest Canary 66.0.3352.0 and reported version 64.0.3282.167 and unable to reproduce this issue by following the steps given above.

on hitting cmd+shift+N, can observe that the incognito window is opening without any lag.
Attached is the screen cast for reference.

Request you to retry the issue on a new chrome profile without any flags/extensions and observe the thread with the observations.

Thanks..

Deleted: 814127.mp4 882 KB

	814127.mp4 882 KB View Download

I can confirm this still occurs when all extensions are removed. It does not occur in canary where my profile does not exist. This is likely related to the length of my chrome profile.

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

Unable to reproduce the issue on mac 10.13.3 using chrome reported version #64.0.3282.167 and latest canary #66.0.3352.0.

Following are the steps followed to reproduce the issue.
------------
1. Opened incognito window both using Cmd+Shift+N and from menu.
2. Observed that the new incognito window opened very quickly.

As the issue is not reproducible from TE-end and it seems it is something specific to profile as per comment #4. Hence, requesting someone from UI>Browser>Profiles team to please have a look into the issue.

Thanks...!!

Thanks for the report!

Can you take a sample by:
1) Open Activity Monitor
2) Find the Chrome process 
3) Open gear menu in toolbar
4) "Sample process"
5) Switch back to Chrome and open an incognito window

Re: comment 4, do you have reason to believe your profile is unusually large?

I took a sample, it opened and generated a window before the incognito opened, does that mean it wasn't captured?

I looked at my profile in Chrome and in Canary and noticed it was  much longer, I don't know if that means it is unusually large.

Deleted: Sample of Google Chrome.txt 526 KB

Sample of Google Chrome.txt 526 KB View Download

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

Symbolized sample attached. +mlamouri@ for MediaEngagementService which appears to be taking much of the main thread's time here.

Deleted: symbolized_814127.txt 745 KB

symbolized_814127.txt 745 KB View Download

+beccahughes@ who can have a look next week.

I also started experiencing this recently with the following user agent:

Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/64.0.3282.186 Safari/537.36

Disabling all extensions and restarting didn't help. However, when I received an update today, the problem immediately went away after the restart. My current version is:

Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.162 Safari/537.36

This no longer occurs for me in the newest version of chrome

This seems to be fixed. Updating the status.