Added support for overriding file browse dialogs by implementing the cef...

Example usage...

    public class SilentDialogHandler : IDialogHandler
    {
        public static string FilePath;
        public bool OnOpenFile(IWebBrowser browser, string title, string default_file_name, List<string> accept_types, out List<string> result)
        {
            result = new List<string>() { FilePath };
            return true;
        }
    }

Then make sure you set it on your view

    webView.DialogHandler = new SilentDialogHandler();

then before you click a browse button, make sure you set the static FilePath field on the SilentDialogHandler class.