Auto merge of #14246 - emilio:servo-url, r=SimonSapin

Urlmageddon

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Still needs a bunch of code in net to be converted in order to get more
advantage of this for images and stuff, but meanwhile this should help quite a
bit with #13778.

Still wanted to get this in.

r? @SimonSapin

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components/script/dom/element.rs

@@ -383,7 +383,7 @@ impl LayoutElementHelpers for LayoutJS<Element> {
                 PropertyDeclaration::BackgroundImage(DeclaredValue::Value(
                     background_image::SpecifiedValue(vec![
                         background_image::single_value::SpecifiedValue(Some(
-                            specified::Image::for_cascade(Some(Arc::new(url)), specified::url::UrlExtraData { })
+                            specified::Image::for_cascade(Some(url.into()), specified::url::UrlExtraData { })
                         ))
                     ])))));
         }