Initialization of extension settings

[Costas Athan]

I'm reading this solution for initializing user options in Chrome extensions on Stackoverflow: https://stackoverflow.com/questions/23638777/provide-initial-settings-for-chrome-extension/23638867#23638867

chrome.storage.local.get({option: "default"}, function(data){
  chrome.storage.local.set(data, /*...*/);
});

My question is when does the set function execute?

My intention is to set the initial values of the settings' variables during the onInstalled event, but avoid resetting them during a browser version update.

[Costas Athan]

I wrote "avoid resetting the options during a browser version update". I should also add and during a version update of the extension itself.