Tree identification - Oregon
This is a Privet (Genus Ligustrum). It appears to be Ligustrum vulgare which is known as Common Privet, or sometimes European Privet.

It is a common woodland understorey shrub in Europe, often planted as garden hedging in urban areas as it is semi-deciduous and responds well to repeated pruning. You could never really call it a tree, it is a shrub species.

The white flowers as you say are quite fragrant and pleasant. They develop into shiny black/dark purple berries.