Oh, that's James Cagney as a crazed gangster, Arthur "Doc" Barker.
Trapped by the feds on the top of a giant tank of Natural gas,he begins shooting down into the tank as the cops close in,shouting,
"Top 'O the world Ma, Top 'O the world!
Think it might have been about the "Ma" Barker Gang.
Yup, "White Heat" 1949.