Chrome Version: 52.0.2743.116 m
OS Version: 10.0

What steps will reproduce the problem?
1. Open a new tab+window, maximize it.
2. Keep opening new tabs until they fill up screen width, and existing tabs shrink a little.
3. Hover mouse over last tab's X button.

What is the expected result?
The X button draws red-filled circle when mouse hovers over, and responds to a click closing the tab.

What happens instead of that?
The X button does not draw red-filled circle when mouse hovers over, and it does not responds to click. The actual hover area is ~1 pixel to the left of X.