Chrome Version: 53.0.2785.57 (Official Build)eb80524ecf0d2051a03f126ee5e7193a44a02327-refs/branch-heads/2785@{#546} 32/64-bit.
OS: Windows (7,8,8.1,10),Linux (14.04 LTS),Mac OS X(10.10.5, 10.11.4).

What steps will reproduce the problem?
1. Launch chrome and navigate to chrome://md-settings page and click on 'Advanced' button.
2. Go to 'Password and form' section, hove the mouse pointer on 'Toggle container' icon and observe.

Tooltip is not displaying for 'Toggle container' icon.
Tooltip should display for 'Toggle container' icon.

Note: Tooltip is not displaying for expand/collapse iron-icon also under 'Languages' section.

This is a non-regression issue, seen from M-47 series.

Kindly review the attached screen-cast for reference.
 

Deleted: Actual Screenshot.png 19.8 KB

	Actual Screenshot.png 19.8 KB View Download

Deleted: Actual behavior.mp4 927 KB

	Actual behavior.mp4 927 KB View Download