Установленный в настройках эмулятора прокси не отражается в webview

Storyboard sb = (Storyboard)btnPause.FindResource("PauseStoryboard");
//to start
sb.Begin(btnPause, true);
//to stop
sb.Stop(btnPause);

<Button x:Name="btnPause" Width="28" Background="LightCyan" Click="btnPause_Click">
    <Image Source="Images\pause.png"></Image>
    <Button.Resources>
        <Storyboard x:Key="PauseStoryboard">
            <ColorAnimation  To="Yellow" Storyboard.TargetProperty="(Button.Background).(SolidColorBrush.Color)" Duration="0:0:1" RepeatBehavior="Forever" AutoReverse="True"/>
        </Storyboard>
    </Button.Resources>
</Button>