Chrome version: 69.0.3474.0 (Official Build) Revision 07ea11a69a583156cf0601a4a2f6253b84689574-refs/branch-heads/3474@{#1}(32/64-bit)
OS: Windows 10

What steps will reproduce the problem?
1. Launch chrome,and observe tabstrip area
 
Actual: Unable to differentiate as single tab doesn't have outline
Expected: Single tab should have an outline to differentaite

This is regression issue, broken in ‘M 69’ and will soon update other info:
Good build: 69.0.3472.0  (Revision: 569949).
Bad build: 69.0.3473.0 (Revision: 570288).

You are probably looking for a change made after 570216 (known good), but no later than 570235 (first known bad).

Narrow Bisect info : 
https://chromium.googlesource.com/chromium/src/+log/3c16d9d466102e0839cad4e70cea850107143ca4..64c540a750df6adb453c0f8e6e63800d8948d04c?pretty=fuller&n=50

Suspecting: r570226 from Narrow bisect

@kylixrd: Could you please help to reassign if your change is not the cause for this change.

Note:
1.Unable to provide bisect using per-revision script,Hence providing bisect with old script.
2.Issue is not seen on Windows (7,8,8.1),Linux (14.04 LTS) and Mac(10.12.6,10.13.1,10.13.6)OS
 

Deleted: Actual_screenshot.png 239 KB

	Actual_screenshot.png 239 KB View Download

Deleted: Expected_screenshot.png 272 KB

	Expected_screenshot.png 272 KB View Download