DevTools: [Overrides] Fix iPad 3/4 UA string

R=aandrey, eustas
BUG=322470

Review URL: https://codereview.chromium.org/83793009

git-svn-id: svn://svn.chromium.org/blink/trunk@162622 bbb929c8-8fbe-4397-9dbb-9b2b20218538