Refresh existing Customizer session

[postmastersteve]

When a user has two browser windows or tabs open (Customizer in one, site front end in the other) they invalidate their original Customizer session any time they interact with the ProPhoto Bar. For example, using the ProPhoto Bar inspector to edit a block, that window loads the Customizer and throws the 'multiple sessions' error. The user clicks to bypass and makes changes. They save and view their site again, but the other tab/window with the original Customizer open loses any work that wasn't saved, or any new work that is done before taking an action to save or navigate.

This is really frustrating for users, but can also lead to data loss when the original tab/window has work that hasn't been saved.

Proposing that any actions in another browser tab/window that would load the Customizer would instead update the existing tab/window with the Customizer already open.

This is similar to the behavior of hosting account File Managers, like when a new tab is opened to upload a file - when you click "back to File Manager" the original tab is refreshed.

[postmastersteve]

+1 Erin ticket 170068

[postmastersteve]

+1 Matthew K McMasters ticket 172080

[postmastersteve]

+1 sharee ticket 172062