[webkit-dev] Back/forward cache for pages with unload handlers

[Geoffrey Garen]

> Given some of our (Chromium-team) recent investigation into the  
> contents of unload handlers, I'm not sure how much this move will  
> help users, even if you don't revert it.  Lots of unload handlers  
> busy-wait while doing async XHR in order to try to guarantee  
> delivery of tracking pings.  Authors will probably elect to copy  
> this code to the pagehide handler rather than moving it, and the  
> experience for users is still going to be extremely sluggish  
> navigation out of these pages.

While it's great that you've made improvements for unload handlers (or  
maybe not-so-great, since you made them only in v8), this seems like a  
non-sequitor to a discussion of the back-forward cache.

Prior to r48388, things that could make the back button slow:
1. An unload handler in the page you're leaving.
2. Reloading the page you're going back to.

Post r48388, things that could make the back button slow:
1. An unload handler in the page you're leaving.

Geoff