[2/3]dwrite: build non-system font collections as a list of font families

[Nikolay Sivov]

On 09/09/2014 04:10 AM, Aric Stewart wrote:
> @@ -920,6 +939,8 @@ static UINT32 WINAPI dwritefontcollection_GetFontFamilyCount(IDWriteFontCollecti
>   {
>       struct dwrite_fontcollection *This = impl_from_IDWriteFontCollection(iface);
>       TRACE("(%p)\n", This);
> +    if (This->family_count)
> +        return This->family_count;
>       return This->count;

This looks particularly suspicious, probably naming needs some work. 
Other parts need to be improved as well I think, like avoiding 
impl_from_* in your own internal functions.