ChromeSafariBrowser

     import 'package:flutter/material.dart';         
     import 'package:flutter_inappwebview/flutter_inappwebview.dart';

     class MyInAppBrowser extends InAppBrowser {

       @override
       Future onLoadStart(String url) async {
         print("\n\nStarted $url\n\n");
       }

       @override
       Future onLoadStop(String url) async {
         print("\n\nStopped $url\n\n");
       }
     
       @override
       void onLoadError(String url, int code, String message) {
         print("\n\nCan't load $url.. Error: $message\n\n");
       }

       @override
       void onExit() {
         print("\n\nBrowser closed!\n\n");
       }

     }

     class MyChromeSafariBrowser extends ChromeSafariBrowser {
     
       MyChromeSafariBrowser(browserFallback) : super(bFallback: browserFallback);

       @override
       void onOpened() {
         print("ChromeSafari browser opened");
       }

       @override
       void onLoaded() {
         print("ChromeSafari browser loaded");
       }

       @override
       void onClosed() {
         print("ChromeSafari browser closed");
       }
     }

     void main() => runApp(new MyApp());

     class MyApp extends StatefulWidget {
       final ChromeSafariBrowser browser = new MyChromeSafariBrowser(new          
       MyInAppBrowser());

       @override
       _MyAppState createState() => new _MyAppState();
     }

     class _MyAppState extends State<MyApp> {

       @override
       void initState() {
         super.initState();
       }

       @override
       Widget build(BuildContext context) {
         return MaterialApp(
           home: Scaffold(
             appBar: AppBar(
               title: const Text('ChromeSafariBrowser Example'),
             ),
             body: Center(
               child: RaisedButton(
                   onPressed: () async {
                     await widget.browser.open(
                         url: "https://flutter.dev/",
                         options: ChromeSafariBrowserClassOptions(
                             androidChromeCustomTabsOptions:          
                             AndroidChromeCustomTabsOptions(addShareButton: 
                             false),
                             iosSafariOptions: 
                             IosSafariOptions(barCollapsingEnabled: true)));
                   },
                   child: Text("Open Chrome Safari Browser")),
             ),
           ),
         );
       }
     }