With Android 5.0 Lollipop component WebView Chromium-based it separating from the operating system to update through Google Play so thus the component used by many applications to display web pages receive security, new features and performance improvements without having to wait for manufacturers to update their device.
This continued as well with 6.0 Android Marshmallow, but with 7.0 Android Nougat There are new features. Starting with the release of 51 chrome and Android N will be the browser Google responsible for provide and maintain up-to-date the WebView component.
The Chrome for Android APK will also integrate the WebView, which It will improve the use of the device memory having no hand the process of Chrome and the WebView and also reduce bandwidth necessary to keep WebView to date, since there will be to update two applications (Chrome and WebView), now only having updated Chrome we have updated the WebView. That Yes, this is true while we have Chrome installed on your device, If uninstall Chrome operating system will begin to use and update the independent as usual WebView.
Another novelty is that the user can choose implementation WebView use Android development options. You may choose any version of Chrome compatible (Dev, Beta, or stable) or choose the implementation available on Google Play Webview-independent.