Starting in Windows 7, applications can display a progress notification in
the taskbar. This class wraps around the native functionality to do this.
Sets the taskbar progress state and value for this window. The currentValue
and maxValue parameters are optional and should be supplied when |state|
is one of STATE_NORMAL, STATE_ERROR or STATE_PAUSED.
@throws NS_ERROR_INVALID_ARG if state is STATE_NO_PROGRESS or
STATE_INDETERMINATE, and either currentValue or maxValue is not 0.
@throws NS_ERROR_ILLEGAL_VALUE if currentValue is greater than maxValue.
Stop displaying progress on the taskbar button. This should be used when
the operation is complete or cancelled.
Display a cycling, indeterminate progress bar.
Display a determinate, normal progress bar.
Display a determinate, error progress bar.
Display a determinate progress bar indicating that the operation has
paused.