Growler- a vessel in which beer is fetched- U. S. slang. OED.
Another quote, from the NY Herald, 29 Jul. 1888- "The employment by hands in a number of factories, of boys and girls, under ten and thirteen years, to fetch beer for them, or in other words, to rush the growler."
No real help on origin.
H. L. Mencken, in "The American Language," regards the term as American.

Why do American seamen call a small iceberg a growler?