Escaping CSS string with ember JS not working

like many people (I think), I get warnings in console when binding style attributes to elements in my templates.

For example, I got an ember view containing a div which has this style attribute :

style="{{view.isClosing}};"

Now, I get the warning that this string is not escapes properly and can makes that vulnerable to XSS attacks.

I went to this link : http://ift.tt/1D1H48Q

And then tried putting this in my view :

isClosing: Ember.computed('display', function () {
    if (this.get('conv.isClosing')) {
        return new Ember.Handlebars.SafeString("display:");
    } else {
        return new Ember.Handlebars.SafeString("display: " + this.get('display'));
    };
}),

The warning does not disappear, and when I try doing it with the function escapeCSS as they say in the doc, it tells me that escapeCSS is not defined. Now what is this function and how should I do it?

Thank you