If I set the style on any text in a `BrowserWindow` as such:

```
P {
   font-family: cursive;
}
```

...I would expect that text to take on a "cursive" look, much as it does when I apply the same style to a page loaded in Chrome Browser.

However in Electron 1.4.12 on Mac it looks like it's `serif`.

`cursive` is one of the W3C's five standard styles along with `serif`, `sans-serif`, `monospace`, and `fantasy` [1]. All of these work as expected in Electron except `cursive`.

It seems it should work just like the others. I presume it's just an omission somewhere?

Thanks!

[1] https://www.w3.org/wiki/CSS/Properties/font-family
atom/browser/web_contents_preferences.cc
WebContentsPreferences* self;
  if (!web_contents)
    return false;
  self = FromWebContents(web_contents);
  if (!self)
    return false;
  base::DictionaryValue& web_preferences = self->web_preferences_;
  bool sandboxed = false;
  web_preferences.GetBoolean("sandbox", &sandboxed);
  return sandboxed;
}
void WebContentsPreferences::OverrideWebkitPrefs(
    content::WebContents* web_contents, content::WebPreferences* prefs) {
  WebContentsPreferences* self = FromWebContents(web_contents);
  if (!self)
    return;
  bool b;
  if (self->web_preferences_.GetBoolean("javascript", &b))
    prefs->javascript_enabled = b;
  if (self->web_preferences_.GetBoolean("images", &b))
    prefs->images_enabled = b;
  if (self->web_preferences_.GetBoolean("textAreasAreResizable", &b))
    prefs->text_areas_are_resizable = b;
  if (self->web_preferences_.GetBoolean("webgl", &b))
    prefs->experimental_webgl_enabled = b;
  if (self->web_preferences_.GetBoolean("webSecurity", &b)) {
    prefs->web_security_enabled = b;
    prefs->allow_displaying_insecure_content = !b;
    prefs->allow_running_insecure_content = !b;