I'm developing SharePoint client web part in SharePoint Add-in(app), client web part create an iframe to open a page in the add-in sub-site, the problem is the browsers see this as different security zone which cause to ask for authentication.
I solved the problem on IE by setting the DNS of the add-in site the same of SharePoint site, SharePoint site: contoso.com, Add-in Site: AddInID.constoso.com, but the problem still exist on google chrome.
Any idea of how can i solve this?