The alignment for notifications is controlled by DesktopPopupAlignmentDelegate, which makes the decision based on the display::Display::work_area() of the primary display. It seems like the work area wrongly includes the taskbar in this case.

+derat, marcheu -- any idea?

I suspect that neither Stephane nor I are going to know anything about Chrome's display-related code on non-Linux-based platforms. :-)

With that said... It looks like ui/display/win/display_info.cc gets this from MONITORINFOEX.rcWork. https://msdn.microsoft.com/en-us/library/windows/desktop/dd145066(v=vs.85).aspx says rcWork is "A RECT structure that specifies the work area rectangle of the display monitor that can be used by applications, expressed in virtual-screen coordinates. Windows uses this rectangle to maximize an application on the monitor. The rest of the area in rcMonitor contains system windows such as the task bar and side bars. Note that if the monitor is not the primary display monitor, some of the rectangle's coordinates may be negative values."

No idea why it'd be returning something different on Windows 10, though.

Thanks! +robliao in case he has any ideas

Mike, have you set your taskbar to auto-hide by any chance?

Autohide would have been my first question :-)

No feedback on this in several months so marking WontFix.

Also native notifications are coming to Windows at some point in the future which may solve this.

Sorry about not responding earlier on the autohide question. For the record, if anyone comes past this in the future, I don't have autohide enabled.