core_useragent::get_browser_version_classes does not distinguish Chrome and Safari and don't know Edge

The unit tests cover the code well. Do a quick sanity-check of Moodle in Chrome on desktop and Android. 1. Check the body class is replaced correctly, open the browser's debug window and check for body's class, depend on the browser, class name should replace correctly: Google Chrome (Mac & Window) : The class chrome should exist, safari class should be removed.  Google Chrome (Android)  : The class chrome, android should exist, safari class should be removed. Microsoft Edge : The class  edge android should exist, safari class should be removed. Mobile safari:  The class  ios  should exist,  safari  class should be removed. Other browsers:  Should stay the same as before.   2.  We removed the safari class from the activity chooser dialog, so we will check to make sure it's display same as before. Using iPhone4S or any iOS device with height  639px or lower. Create a course using Boost or  Bootstrap Base theme. Navigate to the course. Click on "Add an activity or resource". The margin around Add and Cancel button should be displayed as before ( 45px ).