Chrome Version: 55.0.2883.21 (Official Build)b9eabca6f064bcaa5aa645e4b3eaba90cf47a43c-refs/branch-heads/2883@{#201} 32/64-bit.
OS: Windows (7,8,8.1,10),Linux (14.04 LTS),Mac OS X(10.10.5, 10.11.4).

Precondition: Navigates to few webpages such that history gets generated on chrome://history page.

What steps will reproduce the problem?
1. Launch chrome and navigate to chrome://history page.
2. Keep focus on 'Actions' menu icon and restore down the browser.
3. Resize the browser from RHS to LHS in such a way that 'Actions' icon gets hide.
4. Press 'Enter' key to open menu list, Click on horizontal scroll bar of menu list and observe.

Unnecessary vertical scroll bar appears on Actions menu list.
Vertical scroll bar should not appear on Actions menu list.

This is a regression issue, broken in M-55 series, below is manual regression range.

Good build: 55.0.2875.0
Bad build: 55.0.2876.0

Narrow bisect:
https://chromium.googlesource.com/chromium/src/+log/864454fb784c52c1202410dc28799c8dc0f9ad0c..649e22b29fe50f3616c93850d1dd77e187da5d52?pretty=fuller&n=100

Suspecting: r421777

Kindly review the attached screen-cast for reference.
 

Deleted: Actions Menu Screenshot.png 18.0 KB

	Actions Menu Screenshot.png 18.0 KB View Download

Deleted: Actual behavior.mp4 1.3 MB

	Actual behavior.mp4 1.3 MB View Download

Deleted: Expected behavior.mp4 1.4 MB

	Expected behavior.mp4 1.4 MB View Download