Block Editor: Respect AUTOSAVE_INTERVAL value

[aduth]

WordPress specifies the duration after which an autosave should occur in an editing environment via its AUTOSAVE_INTERVAL constant, defaulting to 60 seconds:

​https://github.com/WordPress/wordpress-develop/blob/5d92e0c0a950399c53294a41000305ddcf47efb5/src/wp-includes/default-constants.php#L343-L345

In the development of the Gutenberg block editor, a value of 10 seconds was used instead for a more immediate save. This appears to have been persisted over to its merge into core:

​https://github.com/WordPress/wordpress-develop/blob/c4bffce143d824e0dea0815fcf8adb304fd574e6/src/wp-admin/edit-form-blocks.php#L262

For compatibility's sake with the existing constant, should one of the following be considered?

• Change the default value of AUTOSAVE_INTERVAL to 10 seconds or another value (with consideration of impact on dependants, e.g. ​Customize screen)
• Assign the block editor as a factor of the AUTOSAVE_INTERVAL, e.g. AUTOSAVE_INTERVAL / 6 to keep the 10 second duration, assuming an unchanged default
• Use the existing default 60 seconds value for the block editor.

[youknowriad]

This doesn't seem ready and also not critical.

[youknowriad]

I just went with the simplest approach for now which is to respect whatever value is set in AUTOSAVE_INTERVAL

[swissspidy]

For compatibility's sake with the existing constant, should one of the following be considered?

If necessary, we could add a new filterable wp_get_autosave_interval() function, similar to wp_doing_ajax(), to make tweaking per context easier.

[adamsilverstein]

For context, my original autosave PR respected AUTOSAVE_INTERVAL, however after this discussion the interval was set back to 10: ​https://github.com/WordPress/gutenberg/pull/6257/commits/d795e1db8ff040dced0afc6de6baace3521246ec

[adamsilverstein]

autosave.patch​ looks good to me and restores the long documented and expected behavior of respecting the AUTOSAVE_INTERVAL constant.

[pento]

In 44504:

Block Editor: Obey the AUTOSAVE_INTERVAL constant.

Props youknowriad.
Fixes #45262.