I noticed a macro REQUEST_DEBUG in WebCore/loading/loading.cpp which when turned on dumps the requests which are loaded through WebKit.
This works successfully for some requests (e.g., image requests coming out of an <img> tag) but not for others (e.g., <iframe> requests for the URL specified in the "src" attribute).
Is there another chokepoint which will dump *all* requests and not just some?

Thanks!