WebView is deprecated since OS X 10.14, replacement WKWebView is not used

[kqr]

References:

WebView deprecation: https://developer.apple.com/documentation/webkit/webview

WKWebView documentation: https://developer.apple.com/documentation/webkit/wkwebview

I'm unfortunately not well versed enough in OS X APIs to submit a pull request.

(The reason this matters to me, besides support for as many platforms as possible, is that I'd like to magnify the page in the window, which I haven't figured out how to do with WebView, only WKWebView.)