Add base_url and namespaces to style::Stylesheet

components/script/dom/htmlmetaelement.rs

@@ -100,6 +100,8 @@ impl HTMLMetaElement {
                     *self.stylesheet.borrow_mut() = Some(Arc::new(Stylesheet {
                         rules: vec![CssRule::Viewport(Arc::new(RwLock::new(translated_rule)))].into(),
                         origin: Origin::Author,
+                        base_url: window_from_node(self).get_url(),
+                        namespaces: Default::default(),
                         media: Default::default(),
                         // Viewport constraints are always recomputed on resize; they don't need to
                         // force all styles to be recomputed.