Xamarin Forms Pending ProgressBar WebView[Tutorial 10]

Step1:
MainPage.Xaml

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:local="clr-namespace:AwesomeWebView"
             x:Class="AwesomeWebView.MainPage"
              NavigationPage.HasNavigationBar="false">

 
 <AbsoluteLayout>

        <StackLayout AbsoluteLayout.LayoutFlags="All"
                   AbsoluteLayout.LayoutBounds="0,0,1,1">

            <WebView x:Name="browser"
               VerticalOptions="FillAndExpand"
               Navigating="WebOnNavigating"
               Navigated="WebOnNavigated"/>

        </StackLayout>


        <Frame AbsoluteLayout.LayoutFlags="PositionProportional"
           AbsoluteLayout.LayoutBounds="0.5,0.5,AutoSize,AutoSize"
           x:Name="loading"
           BackgroundColor="Gray"
           Opacity="0.9"
           IsVisible="True">
            <StackLayout>
                <ActivityIndicator IsRunning="True"/>
                <Label Text="Loading..."
               TextColor="White"/>
            </StackLayout>
        </Frame>

    </AbsoluteLayout>        
</ContentPage>

Step2:

MainPage.Xaml.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Xamarin.Forms;

namespace AwesomeWebView
{
 public partial class MainPage : ContentPage
 {
  public MainPage()
  {
   InitializeComponent();
            browser.Source = "https://giphy.com/search/smiling";
        }


        void WebOnNavigating(object sender, WebNavigatingEventArgs s)
        {
            loading.IsVisible = true;
        }

        void WebOnNavigated(object sender, WebNavigationEventArgs s)
        {
            loading.IsVisible = false;

        }

    }
}

Step 3: Holaa!!!! No Steps Tutorial Completed :D