Buried in the flags of the latest release of Chrome Dev, v46, is a toggle that allows you to tweak the progress bar animation that you see when loading webpages. The default setting is equivalent to "disabled," but you can try it out and see how it looks.
There are now 4 different options: disabled (which is default), linear, smooth, and fast start. Disabled just leaves things the way they have been for a while. Fast start is like smoother but is set to work faster in the first portion of the page load and slower as it completes.
Smooth, as you might expect, is basically the default animation but at a higher framerate that will look more appealing. Linear, which was added after the initial v46 release, is a slightly lower framerate version of smooth that is nearly impossible to tell apart when run at regular speeds.
I have a couple of GIFs to give you an idea of how it looks, though the smooth setting will look even smoother on your device due to framerate limitations inherent to the GIF format.
Now, the second example also happens to be a time when the page loaded faster. The thing to look for is that the progress bar advances in a far less choppy way in the case of smooth while it jumps in chunks by default.
So why isn't one of the smooth variants set as the default choice? Well, first of all, it isn't clear which of the three smooth choices is best. Further, as discussed on the issue tracker, some of the implementations caused pretty meaningful slowdowns in page load time. Linear is probably your best bet if you want things to look nice but not affect performance.
- Luca Cauterucci