Bug 60017

Summary:	PreloadScanner should fetch iframes
Product:	WebKit	Reporter:	Tony Gentilcore <tonyg>
Component:	WebCore Misc.	Assignee:	Nobody <webkit-unassigned>
Status:	NEW ---
Severity:	Normal	CC:	ap, ddkilzer, koivisto, simonjam, skyul
Priority:	P2	Keywords:	Performance
Version:	528+ (Nightly build)
Hardware:	All
OS:	All
Bug Depends on:	49246
Bug Blocks:

Description Tony Gentilcore 2011-05-03 03:14:13 PDT

The PreloadScanner should fetch subdocuments (iframes). To do this, I believe we need to allow main resources in the memory cache, then the fix should be trivial.

We might also explore preload scanning within the subframe.

FWIW, this will also let us pass browserscope's "|| Script Iframe" test here: http://www.browserscope.org/?category=network

Comment 1 Alexey Proskuryakov 2011-05-03 10:01:27 PDT

Is it common that iframes contain anything worthwhile? It seems that delaying loading them might be best.

Comment 2 David Kilzer (:ddkilzer) 2011-05-03 11:22:00 PDT

(In reply to comment #1)
> Is it common that iframes contain anything worthwhile? It seems that delaying loading them might be best.

Or maybe only preload them if they're from a similar domain, or set their priority higher if they're from a similar domain?

Comment 3 Antti Koivisto 2011-05-03 13:56:03 PDT

(In reply to comment #1)
> Is it common that iframes contain anything worthwhile? It seems that delaying loading them might be best.

Iframe content is part of the page content and we want the full content to be loaded as quickly as possible. "Worthwhile" or not, it doesn't help anyone if it loads slowly.

Comment 4 Alexey Proskuryakov 2011-05-03 14:07:57 PDT

Total load time is not the only metric to improve.

What I'm saying is that prefetching iframes (and even more so, their subresources) has a lot of potential to significantly increase the time until the page is usable.