There is a certain benefit to Google’s strategy of rolling out updates only in waves rather than all at once. When a bug is uncovered early on, the update can be halted to prevent affecting all users. That was the exact scenario that faced Android users when the latest Chrome 79 version started rolling out, causing a specific set of apps to lose their data. While the update has now been halted the damage has unfortunately been done to those affected by the bug.
To be clear, it isn’t Chrome 79 itself that has a bug nor does using it to browse the web cause any data loss. It is only those apps that use Chrome’s web rendering component, a.k.a. WebView, as their primary or only interface are bitten by it. While Android does allow apps to use other kinds of web views, Chrome’s is the most common because it is expected to be always there.
Unfortunately, Chrome 79 introduced a behavior change that led to data loss because of a bug. This new version apparently changed the location where web data is stored but data stored by third-party apps using WebView didn’t get moved properly. Technically, the data is still there in the old location but the apps will always report that there is no data because they can’t see them in the proper location.
The coverage of the bug is unknown at this point. Apps that use the Apache Cordova (a.k.a. PhoneGap) framework to turn web apps into mobile apps were one of the first to get bitten by it. Judging by the noise on the Chrome bug report, there is a good number of disgruntled developers with very irate users. Fortunately, user data that are stored in the cloud aren’t affected.
Google says that the update has been halted at 50%. It is, however, still undecided on how to proceed moving forward to fix the bug or if it’s even possible to recover the misplaced data. It is definitely a rather disappointing turn of events for an update to an app that is essential not just to web browsing but to other apps as well.