Chrome Version: 56.0.2911.0 (Official Build)f902396696551c0a1cac9fd9ad3f9a3faf875aff-refs/heads/master@{#430171} 32/64-bit.
OS: Windows(7,8,10), Mac(10.10.5, 10.11.4), Linux(14.04 LTS).

Precondition: Navigates to 30-35 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 first URL or 'Actions' icon using 'Tab' key from keyboard.
3. Press and hold the down arrow key from keyboard and observe the vertical scroll bar.

Scrolling is not smooth (it's stuck in between).
Scrolling should be smooth.

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

Good build: 55.0.2867.0
Bad build: 55.0.2868.0

Narrow bisect:
https://chromium.googlesource.com/chromium/src/+log/eedb95b1a034bb392ed83e84ee690395a0db3e27..92a3e96937407fa835de27f9368824029e625973?pretty=fuller&n=100

Suspecting: r419956

Kindly review the attached screen-cast for reference.
 

Deleted: Actual behavior.mp4 816 KB

	Actual behavior.mp4 816 KB View Download