Fix bug 1491006: Only set up canvas once (#1080)
Fix bug 1491006: Only set up canvas once (#1080)


jotes/pontoon,mathjazz/pontoon,mozilla/pontoon,mozilla/pontoon,jotes/pontoon,mathjazz/pontoon,mathjazz/pontoon,mozilla/pontoon,jotes/pontoon,mozilla/pontoon,mathjazz/pontoon,mathjazz/pontoon,mozilla/pontoon,jotes/pontoon