Problem description

According to Material guidelines ALL(with controls also) single line list items must be 48px height and 40px when in dense mode. Only exception is when avatar element is present it can be 56px height.
https://material.io/guidelines/components/lists.html#lists-specs

Link to minimally-working code that reproduces the issue

Versions

• Material-UI: next
• React: 15.4.0
• Browser: Chrome 56