Regression range: https://chromium.googlesource.com/chromium/src/+log/11f4ce4066cbd1bda4f00ea56e6d9b41ac27adcb..50518fc77cc0e960c20137a16406cd0d10056890

Maybe https://chromium.googlesource.com/chromium/src/+/200d56fbfb923ba7fb14d7374e198ebea272fbf6 ?

ccameron@: Can you please check, if this issue could be caused by your change?

Thanks :)

Maybe interesting:

The initial regression range is https://chromium.googlesource.com/chromium/src/+log/11f4ce4066cbd1bda4f00ea56e6d9b41ac27adcb..50518fc77cc0e960c20137a16406cd0d10056890 from my comment #2. There it flickers when you close a NTP.

But with the regression range https://chromium.googlesource.com/chromium/src/+log/faf816e3de6999c544d30fe1c8d07700642f1619..ec54e1ca07094b9b8e737d9e87e72555ef2215b5 the flicker is much more prominent, because it also flickers when you open a NTP.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/1cdbef88a7ade4a852488ea26ee3af26efdedda6

commit 1cdbef88a7ade4a852488ea26ee3af26efdedda6
Author: Christopher Cameron <ccameron@chromium.org>
Date: Thu May 24 05:19:23 2018

MacViews: Do not set delegating layer background color

Setting the background color on delegated layers can cause artifacts
(only non-tiled areas get the background color). This also appears
not to have been necessary.

Bug:  845968 ,  840173 
Change-Id: If8eca7d3eb793952a9a606a2d27683b02d2c4b3f
Reviewed-on: https://chromium-review.googlesource.com/1071117
Reviewed-by: Sidney San Martín <sdy@chromium.org>
Commit-Queue: ccameron <ccameron@chromium.org>
Cr-Commit-Position: refs/heads/master@{#561390}
[modify] https://crrev.com/1cdbef88a7ade4a852488ea26ee3af26efdedda6/content/browser/renderer_host/browser_compositor_view_mac.mm
[modify] https://crrev.com/1cdbef88a7ade4a852488ea26ee3af26efdedda6/content/browser/renderer_host/render_widget_host_view_mac.mm

Able to reproduce this issue on Mac OS 10.13.3 on the reported version 68.0.3438.0 and the issue is fixed on the latest Canary 68.0.3440.0.

By enabling #views-browser-windows flag, cannot observe any glitches while opening/closing new tabs.
Attached is the screen cast for reference.

Hence adding TE verified labels as the fix is working as intended.

Thanks..

Deleted: 845968-M68-CL.mp4 1.4 MB

	845968-M68-CL.mp4 1.4 MB View Download

Marking Verified per #4 and #5.