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
}
  if (self->web_preferences_.GetBoolean("allowDisplayingInsecureContent", &b))
    prefs->allow_displaying_insecure_content = b;
  if (self->web_preferences_.GetBoolean("allowRunningInsecureContent", &b))
    prefs->allow_running_insecure_content = b;
  const base::DictionaryValue* fonts = nullptr;
  if (self->web_preferences_.GetDictionary("defaultFontFamily", &fonts)) {
    base::string16 font;
    if (fonts->GetString("standard", &font))
      prefs->standard_font_family_map[content::kCommonScript] = font;
    if (fonts->GetString("serif", &font))
      prefs->serif_font_family_map[content::kCommonScript] = font;
    if (fonts->GetString("sansSerif", &font))
      prefs->sans_serif_font_family_map[content::kCommonScript] = font;
    if (fonts->GetString("monospace", &font))
      prefs->fixed_font_family_map[content::kCommonScript] = font;
  }
  int size;
  if (self->web_preferences_.GetInteger("defaultFontSize", &size))
    prefs->default_font_size = size;
  if (self->web_preferences_.GetInteger("defaultMonospaceFontSize", &size))
    prefs->default_fixed_font_size = size;
  if (self->web_preferences_.GetInteger("minimumFontSize", &size))
    prefs->minimum_font_size = size;
  std::string encoding;
  if (self->web_preferences_.GetString("defaultEncoding", &encoding))
    prefs->default_encoding = encoding;
}
}