The browser may add the qualifier "if-heavy" to the Chrome-Proxy-Accept-Transform header to request that data-heavy pages be transformed.

For example:

Chrome-Proxy-Accept-Transform: lite-page;if-heavy

means convert the page to a lite page if the page would otherwise be data heavy. 

Likewise, a transformed response should have the Chrome-Proxy-Content-Transform header with the qualifier "heavy".

For example:

Chrome-Proxy-Content-Transform: lite-page;heavy

means that the page was converted to a lite page because it was data heavy.