Chrome Version: (copy from chrome://version)
OS: (e.g. Win7, OSX 10.9.5, etc...)

What steps will reproduce the problem?
(1) Enable VoiceOver
(2) Open a NTP
(3) Use Option Ctrl Right to navigate through the NTP, and once you reach the notifications button, press enter or space to open it. Then try to navigate through that UI with VoiceOver. 

When I use VoiceOver to open the notifications center, I can't access the close buttons for the notifications using the screen reader. I can get to them using just tab, but I get no spoken feedback about what the button is, or the fact that it's a button. We need to ensure these buttons are accessible to VoiceOver (and all screen readers). 

Also, when I use VoiceOver to access the notifications button, then press space to expand the UI, I can't easily enter it with keyboard and VoiceOver. The focus doesn't behave right. Once it's expanded, if I press Option Ctrl Right to move linearly, I should be brought into that UI. Instead, I move to the next icon on the top of the NTP. I eventually reach the notifications UI if I overshoot it and then navigate backwards linearly, which is odd. At that time, it just says "frame 0" as the title of the UI, when it should really say "notifications popup" or something like that. 
 

Chrome Version:  56.0.2924.87
OS: Mac

What steps will reproduce the problem?
(1) Enable VoiceOver
(2) Open a NTP
(3) Use Option Ctrl Right to navigate through the NTP, and once you reach the notifications button, press enter or space to open it. Then try to navigate through that UI with VoiceOver. 

When I use VoiceOver to open the notifications center, I can't access the close buttons for the notifications using the screen reader. I can get to them using just tab, but I get no spoken feedback about what the button is, or the fact that it's a button. We need to ensure these buttons are accessible to VoiceOver (and all screen readers). 

Also, when I use VoiceOver to access the notifications button, then press space to expand the UI, I can't easily enter it with keyboard and VoiceOver. The focus doesn't behave right. Once it's expanded, if I press Option Ctrl Right to move linearly, I should be brought into that UI. Instead, I move to the next icon on the top of the NTP. I eventually reach the notifications UI if I overshoot it and then navigate backwards linearly, which is odd. At that time, it just says "frame 0" as the title of the UI, when it should really say "notifications popup" or something like that.