If you're running Chrome Beta or Dev editions, then today's changes probably seem like old hat to you. But for everyone else, the stable version of Chrome 45 is a pretty big deal, because it brings Custom Tabs to essentially everyone who's running Android today (on a modern handset, anyway).
For those who may not remember, Google first announced Custom Tabs at I/O back in May. Essentially, these are pop-out WebView tabs that apps can utilize without actually leaving the foreground, basically launching Chrome within the app. Custom Tabs are designed to be fast, efficient, and completely customizable (so they still feel very much native to the app experience).
Custom Tabs have been available in the Dev build of Chrome since version 44, but now they seem to be ready for primetime use.
While Google didn't announce any other changes for 45 Stable, we can assume that the same enhancements that were found in 45 Beta are also along for the ride.
Update: The new G icon made it into this build:
You can grab the download from APK Mirror now.
The APK is signed by Google and upgrades your existing app. The cryptographic signature guarantees that the file is safe to install and was not tampered with in any way. Rather than wait for Google to push this download to your devices, which can take days, download and install it just like any other APK.
File Name: com.android.chrome-45.0.2454.84-245408400-minAPI16.apk
Version: 45.0.2454.84 (245408400)