By Lisa Richwine (Reuters) -Actor Johnny Depp testified on Tuesday that he never struck his ex-wife Amber Heard and was challenging her accusations in a $50 million defamation case to correct the public’s perception and stand up for his children. Speaking softly and slowly for nearly three hours, Depp said in a Virginia courtroom that it was a “complete shock” about six years ago when Heard “made some quite heinous and disturbing” allegations that he became violent during their relationship. “Never did I myself reach the point of striking Ms. Heard in any way, nor have I ever struck any woman …