Grant whispers to me: “Look, you damned Englishman. ’E’s for it.” Uncle John was leanin’ up against the bay, an’ hummin’ that hymn I was tryin’ to tell you just now. He looked different all of a sudden—as if ’e’d got shaved. I don’t know anything of these things, but I cautioned Grant as to his style of speakin’, if an officer ’ad ’eard him, an’ I went on. Passin’ Uncle John in the bay, ’e nods an’ smiles, which he didn’t often, an’ he says, pocketin’ the paper “This suits me. I’m for leaf on the twenty-first, too.”’
This is from "The Madonna of the Trenches" by Rudyard Kipling.
http://www.telelib.com/authors/K/KiplingRudyard/prose/DebtsandCredits/madonnatrenches.html
I don't understand the meaning of ’E’s for it.”
I am glad if someone would kindly teach me.