Chrome Version:51.0.2704.63 (Official Build) 2989ec7055a268f05554172b2207a34c0c842b8d-refs/branch-heads/2704@{#656} (32/64-bit)
OS: Windows (7, 8, 10), Mac(10.10.5, 10.11.4), Linux(14.04 LTS)

Steps:
1. Launch Chrome and open dev-tool on NTP.
2. Go to 'Timeline' section,check 'Screenshot' checkbox and complete the recording.
3. Hover the mouse on the first captured screenshot and observe.

Actual: Outline border of first/initial captured screenshot is not seen.

Expected: Outline border of first/initial captured screenshot should be seen.

This is a regression issue broken in M-51, below is bisect info.

Good build: 51.0.2702.0
Bad build: 51.0.2703.0

Narrow bisect:
https://chromium.googlesource.com/chromium/src/+log/bebeb608346c93d77f496c47cf0df62da80c517e..7f5d299c449f2e0fb0c1b8fda19b1edfa60519e2?pretty=fuller&n=100

Suspecting: r385389 ?

Please help to re-assign if your is not the cause for this issue.

 

Deleted: Actual_result.jpg 128 KB

	Actual_result.jpg 128 KB View Download

Deleted: Expected_result.jpg 136 KB

	Expected_result.jpg 136 KB View Download