The current meaning of “chuffed” is: delighted, pleased, satisfied.
Norman W. Schur’s British English A to Zed (2001) says: “This curious bit of antiquated army slang has two diametrically opposite meanings, depending on the context. One can say chuffed pink (tickled pink) to mean ‘pleased’ or dead chuffed to mean ‘displeased’ or ‘choked’.” The Oxford English Dictionary agrees.
When it originated, some time between 1825–35, “chuffed” meant something negative. By around 1855–60, the meaning changed to something positive.
I’ve also heard someone say, “Well, I’ll be chuffed,” as in “I’ll be damned.”
As Humpty Dumpty said, “A word means whatever I want it to mean.”