Google really, really loves their A/B tests. While the vast majority of users might be seeing one shade of green in the Play Store, another set of users might see a totally different color. Google Chrome for Android works a bit differently, though, as its open source nature and feature flags allow for anyone to participate in the company's public A/B tests. Today, a new commit has appeared on the Chromium gerrit that aims to revamp the tab switcher in Chrome for Android.

As shown in the image above, the tab switcher shows cards lined up horizontally when the user is in landscape mode. On the other hand, the tabs are lined up vertically when the device is in portrait mode. This new commit adds a feature flag (chrome://flags#enable-horizontal-tab-switcher) to always show the horizontal tab switcher when the phone is in portrait mode. The commit description states that a future commit will refine the tab UI in preparation for a "public experiment," so it's clear that Google intends to A/B test this on a segment of its users.

Google Chrome Horizontal Tab Switcher

If we might speculate a bit, I think this sort of change lines up nicely with the rumors that Android P will offer navigation gestures. According to 9to5Google, the next major Android version will offer gestures to navigate the interface like the iPhone X. We've already seen phones like the OnePlus 5T offer similar gestures, and with the recent push towards almost entirely bezel-less devices, we wouldn't be surprised if Android starts to natively offer such a feature. A revamped horizontal tab switcher in Chrome might go along with a horizontal recent apps screen in Android P if this rumor is true.


Update: Commit Merged, Here's a Screenshot

The commit was merged, so we installed the latest Chromium build to see what the horizontal tab switcher would look like in portrait mode. As expected, it's a bit cramped. We expect it to improve in future builds.