With Android P's developer preview out in the wild, everyone's running around like a chicken with its head cut off to find new features that Google didn't explicitly announce. We knew that Autofill was being upgraded, but Google didn't exactly say how. However, thanks to a blog post from password manager Dashlane, we now know at least one feature that's being added – official support for web browsers.
As it stands in Android Oreo, Autofill only works by default within apps. Most password managers let you force Autofill to work in web browsers by enabling accessibility services, but this requires an extra step and isn't the most user-friendly thing.
Per Dashlane's Android Lead Developer, Stan Kocken:
The reason is that Chrome (like Microsoft Edge, Samsung Browser or Firefox, for example) uses a custom render for the web pages you view. This custom render allows high-performance, but prevents the Autofill Engine embedded in Android O from telling identity managers (like Dashlane) certain information, like when the page changes.
However, with Android P, Autofill will work within web browsers by default. Android P enables accessibility services in the background so the user doesn't have to, and this results in a much more seamless experience across the board.
In addition to Dashlane, any other password managers already using Autofill (such as LastPass and 1Password) will be able to update their apps with similar functionality.