Load Chrome extension before loading all elements of the page

I woul开发者_开发技巧d like to load my Chrome extension before all the elements of the page load (instead of after). Is this possible? Thanks!

If by extension you mean content script then the most you can do is set "run_at": "document_start" property in manifest which means

"[content script] files are injected after any files from css, but before any other DOM is constructed or any other script is run."

(read more).

You won't be able to communicate with your background page before the page starts loading though as there is no synchronous message passing.