How can we set break on: ->... when get into Google Devtool, to always get set on for certain URL when it is active, and is left 'as is' (unset) for the rest
Do you mean breaking when JavaScript access specified URL?
yes, breaking when an element attribute is being modified.. user will only need preset it up once for a particular URL, then keep getting set on everytime the url is opened.
I saw this in a video of FB2Mate's fanpage.
You can use a app called XHR Breakpoints
XHR Breapoints allow you to break whenever a server request URL contains a particular value. Add an XHR breakpoint within the Sources tab. Click the + icon and enter a value to break on.