The handling of two state variables had to be adjusted. One is
responsible for signalling that we navigated to a blank page due to the
WebBrowserComponent becoming invisible. The other variable in the
WebView2 implementation stores the URL that we should be navigating to
once the WebView2 instance has been created.
Prior to this commit navigating to the URL requested by goToURL could
fail for two reasons: either because it was called before the underlying
WebView2 instance was created, or because the WebBrowserComponent was
not yet visible.
