Outdoor plant losing leaves

I have this plant in a large pot that I am not sure of what it is, but last year it was fine and this year, it is losing leaves like mad, dozens a day. Also, the former owner suggested it be root pruned some time, but I am not sure when that is supposed to happen, or even what the plant is. Some assistance from you knowledgeable folk is greatly appreciated.

I attached a picture of the leaves up close for ID.

 

Ligustum japonicum. Roots probably froze and died during low temperatures this past winter.

 

Ron, just in case you didn't know...you are awesome. Thanks!