The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/6d56e5b6a0ffc389e46d784bf4a1f64bc7bc6a9b

commit 6d56e5b6a0ffc389e46d784bf4a1f64bc7bc6a9b
Author: wutao <wutao@chromium.org>
Date: Tue Jun 12 16:47:57 2018

Fix tab shape of tabbed pane in kVertical mode

In the kHighlight and kVertical mode, the flat side of the side tab
should be at the window edge, no matter in the LTR or RTL.

Bug:  851742 
Change-Id: Ie78bc55ffa3914b4124a12469b71477cbf8ce6d8
Reviewed-on: https://chromium-review.googlesource.com/1096432
Reviewed-by: Michael Wasserman <msw@chromium.org>
Commit-Queue: Tao Wu <wutao@chromium.org>
Cr-Commit-Position: refs/heads/master@{#566463}
[modify] https://crrev.com/6d56e5b6a0ffc389e46d784bf4a1f64bc7bc6a9b/ui/views/controls/tabbed_pane/tabbed_pane.cc

The bug is marked as P3 or Feature. It should not be merged as M68 is in beta. 
Please contact the approriate milestone owner if you have questions.
Owners: cmasso@(Android), kariahda@(iOS), bhthompson@(ChromeOS), abdulsyed@(Desktop)

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