I'm not aware of any, but I don't see all the changes. Try looking at the history of tab_strip. That said, this looks more like a frame painting issue. That is, doesn't it look like the non-client area (the area behind the tab-strip) isn't painted correctly? I believe that code is in browser_header_painter_ash.cc and related classes.

It looks like the non-client area isn't painted correctly.

Seems only happens when you have theme installed. Also happens on device. I can take a look.

CL breaks this is: https://codereview.chromium.org/2770943002

+danakj@

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/b30c149bc6b38870ca74cb8dcd5fb34e90e75480

commit b30c149bc6b38870ca74cb8dcd5fb34e90e75480
Author: warx <warx@chromium.org>
Date: Wed Mar 29 03:21:07 2017

cros: Fix browser header wrongly drawn frame image

Changes:
Check the code before https://codereview.chromium.org/2770943002, found that when frame_overlay_image_.isNull(), TileImageInt should be called.

BUG= 704636 
TEST=test that bug doesn't happen with theme installed

Review-Url: https://codereview.chromium.org/2770943004
Cr-Commit-Position: refs/heads/master@{#460265}

[modify] https://crrev.com/b30c149bc6b38870ca74cb8dcd5fb34e90e75480/chrome/browser/ui/views/frame/browser_header_painter_ash.cc
[modify] https://crrev.com/b30c149bc6b38870ca74cb8dcd5fb34e90e75480/ui/gfx/canvas.cc
[modify] https://crrev.com/b30c149bc6b38870ca74cb8dcd5fb34e90e75480/ui/gfx/canvas.h

 Issue 707551  has been merged into this issue.

Verified on build 9460.42.0