[Merge] lp:~uriboni/webbrowser-app/undo-close-tab into lp:webbrowser-app

[Olivier Tilloy]

Also, Ctrl+Shift+W exit the application in chromium and firefox on desktop. For consistency with the competition, can we use Ctrl+Shift+T ?
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https://code.launchpad.net/~uriboni/webbrowser-app/undo-close-tab/+merge/275849
Your team Ubuntu Phablet Team is requested to review the proposed merge of lp:~uriboni/webbrowser-app/undo-close-tab into lp:webbrowser-app.