Again, we should be prioritizing the foreground tab's loads so background tabs don't delay it. If we're not doing this, we should file bugs to do so.
Making the browser appear usable as fast as possible -- if possible, even before it's actually usable -- is a critical part of making Chrome startup feel fast. Mozilla learned long ago (to their chagrin) that splash UI on loading is counterproductive from both a real and a perceptual standpoint.
If you're only doing this locally for some one-off thing, that's fine, but there won't be (and shouldn't be) any effort to support this kind of thing in the main repository.
PK