var Storage = (function() { return { save: function(key, value) { return new Promise(function(resolve, reject) { var objToSave = {}; objToSave[key] = value; chrome.storage.local.set(objToSave, resolve); }); }, load: function(key) { return new Promise(function(resolve, reject) { chrome.storage.local.get(key, function(data) { resolve(data[key]); }); }); }, remove: function(key) { return new Promise(function(resolve, reject) { chrome.storage.local.remove(key, resolve); }); } }; })();