Browsers are de-facto windows managers in the unfortunate world we've created where everything is a webapp with 5% of the perf that it'd have as a native app.
I didn't measure it, but switching tabs in an Asus C201 Chromebook sure seemed to have a much lower latency than tab switching (or clicking on a different app in a menubar) for any Linux distro I've ever used on any piece of hardware. That includes this Dell XPS laptop running Ubuntu, which is fast and well-supported with firmware.
I speculate without measuring because switching browser tabs on that Chromebook feels uncanny. It's as if there's some ahead-of-time trick that utilizes the camera to guess my impending trackpad click or keystroke. That makes me think I've gotten used to a fairly high floor of latency on my Linux machines.
Add to that the long battery life while browsing in Chrome. Add to that the fact that I open and close that Chromebook at will with the browser in nearly any state, and it never got hot, crashed, or failed to come back up when I reopened it[1].
Those things being true, it makes more sense from a performance standpoint to use Linux from within Chrome than the other way around. That is-- as long as you spend non-trivial time in a browser, it's more efficient to do Linux-Inside-Chrome than Chrome-Running-Inside-Linux. (And I have never found a Linux Firefox config on any piece of hardware that can reliably play videos on Reddit, which makes me think it's not handling video acceleration properly.)
1: The one exception: when I was running a low-latency audio app on that Chromebook which grabbed exclusive control of ALSA.
It depends on what we mean when we say "Chrome". When the chrome binary is built for ChromeOS, it includes a shell called "ash". It's got a window manager, virtual desks, app launcher, login screen and more. The fact that this all lives in a binary called "chrome" and uses a nontrivial amount of the flags that this post is about is in some ways a historical artifact. The source for it is here [1]. None of that stuff is included in a regular desktop (Windows, Mac, Linux) build of Chrome.
This is sorta how many "embedded" systems with a display work these days. Start a chromium window in kiosk mode at boot and use a webapp for the UI. You'd be surprised how many touchscreens out in the world do exactly this.
