If you want to print out the the storage area of the chrome.storage APIs just type in the following code in the console or better make a Chrome JavaScript snippet and execute it.
// Print out local storage area
chrome.storage.local.get(null, function(all) {
console.log(all)
});
// Print out sync storage area
chrome.storage.sync.get(null, function(all) {
console.log(all)
});