Chrome Version: 53.0.2783.2 (Official Build)65c6178c55984c82fb8bebd4999395c4b364b621-refs/branch-heads/2783@{#3} 32/64-bit.
OS: Windows(7,8,10), Mac (10.10.5)(10.11.4), Linux(Ubuntu 14.04 LTS).

What steps will reproduce the problem?
1. Launch chrome and navigate to chrome://md-settings/ page.
2. Select 'Open a specific page or set page' radio button under 'On startup' section and Click on 'Add a new page' button.
3. Now, give a valid URL in input box (For Ex: www.google.com) and then press 'Enter' key from keyboard and observe.

Nothing happens on pressing the 'Enter' key from keyboard.
URL should get added on pressing the 'Enter' key from keyboard.

This is a non regression issue, seen from M-47 series, as this feature is introduced from build # 47.0.2512.0 

Note: This issue is reproducible for all the overlay on chrome://md-settings page.

Kindly review the attached screen-cast for reference.
 

Deleted: Actual behavior.mp4 938 KB

	Actual behavior.mp4 938 KB View Download