not sure; what theme is that? My recent frame related work shouldn't have made it into 68.

Theme: https://chrome.google.com/webstore/detail/yellowstone-national-park/nacnmgkkmahnhoalacmojjligghbjofa?utm_source=gmail

fyi I couldn't repro -- on Windows 67 or Mac 68 though, don't have a Cros 68 device.

Tentatively to estade@ but please unaccept if you can't repro there.

Okay, I'm going to reopen this, it looks like the toolbar is transparent.
Google Chrome 68.0.3440.76 (Official Build) beta (64-bit)
Peter, perhaps you know a better owner related to themeing and transparency?

Deleted: theme_transparency.png 457 KB

	theme_transparency.png 457 KB View Download

I'm sheriff right now + heavily bandwidth-constrained due to the impending M69 release, and I don't have a CrOS environment to test in.  Any chance you can bisect this?  If we can get a relevant CL I'm sure we can fix :)

I'll have a look soon

I tried to bisect, but all my renderers are crashing; I filed  Issue 872783 .

Mike, are you sure this a regression? I have a fix here[1] but I sort of doubt this ever worked properly.

[1] https://chromium-review.googlesource.com/c/chromium/src/+/1169807

I'm pretty sure the user only noticed this issue recently, but perhaps they changed themes recently?

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/eeddc1fcb0a7897d31eadfddfbf621ce9e9bdaf2

commit eeddc1fcb0a7897d31eadfddfbf621ce9e9bdaf2
Author: Evan Stade <estade@chromium.org>
Date: Fri Aug 10 21:51:10 2018

Browser Themes: always paint an opaque BG color behind toolbar images

for both the active tab and the toolbar. This matches the bookmarks
bar, i.e. PaintBackgroundAttachedMode.

Bug:  866974 
Change-Id: I3a86d2330bf09903f74359e433a4165e3e4d3e8e
Reviewed-on: https://chromium-review.googlesource.com/1171216
Commit-Queue: Evan Stade <estade@chromium.org>
Reviewed-by: Peter Kasting <pkasting@chromium.org>
Cr-Commit-Position: refs/heads/master@{#582350}
[modify] https://crrev.com/eeddc1fcb0a7897d31eadfddfbf621ce9e9bdaf2/chrome/browser/ui/views/tabs/tab.cc
[modify] https://crrev.com/eeddc1fcb0a7897d31eadfddfbf621ce9e9bdaf2/chrome/browser/ui/views/toolbar/toolbar_view.cc