SAN FRANCISCO (Reuters) – Mozilla chief executive Brendan Eich has stepped down amid a controversy over his views on gay marriage, the company said in a blog post on Thursday. The software company, best known for its Firefox Internet browser, came under fire for appointing Eich as CEO last month. Eich has donated money to oppose the legalization of gay marriage, a hot-button issue in recent years. (Reporting by Sarah McBride)