What were the names of the two polite chipmunks featured in the old Warner Brothers cartoons?

You may be thinking of Mac 'n' Tosh, who were actually gophers. They debuted in the 1947 WB cartoon 'The Goofy Gophers'. They were WB's answer to Chip 'n' Dale, who were Disney characters.

Yes, the two polite chipmunks appear to be twin gophers named Mac and Tosh:

A BONE FOR A BONE Warner Brothers cartoon
The two polite chipmunks are playing gin in their burrow when a bone comes crashing down on them courtesy of a dog who just buried it. They try and appeal to the dog to bury his femur somewhere else but the stubborn dog decides he should bury it where he wants it and the war is on as the chipmunks give the dog plenty of grief before he decides to pack his bags and leave!

Two polite twin gophers are in their underground home, playing gin, when a dog buries his bone right on top of them. They try to negotiate with the dog so that he will bury the bone somewhere else. But the dog refuses to be cooperative.

http://www.imdb.com/title/tt0043354/plotsummary
https://en.wikipedia.org/wiki/Goofy_Gophers

The Goofy Gophers

http://www.toonopedia.com/gophers.htm

Mac and Tosh were their individual names.
http://www.toonopedia.com/gophers.htm