2 files changed, 15 insertions, 17 deletions

diff --git a/components/script/dom/cssstyledeclaration.rs b/components/script/dom/cssstyledeclaration.rs
index c119f8a70e6..c8be4f560a6 100644
--- a/components/script/dom/cssstyledeclaration.rs
+++ b/components/script/dom/cssstyledeclaration.rs
@@ -12,7 +12,6 @@ use dom::element::Element;
 use dom::node::{Node, NodeDamage, window_from_node};
 use dom::window::Window;
 use parking_lot::RwLock;
-use servo_atoms::Atom;
 use std::ascii::AsciiExt;
 use std::sync::Arc;
 use style::parser::ParserContextExtraData;
@@ -74,12 +73,12 @@ impl CSSStyleDeclaration {
                            CSSStyleDeclarationBinding::Wrap)
     }
 
-    fn get_computed_style(&self, property: &Atom) -> Option<DOMString> {
+    fn get_computed_style(&self, property: PropertyId) -> DOMString {
         let node = self.owner.upcast::<Node>();
         if !node.is_in_doc() {
             // TODO: Node should be matched against the style rules of this window.
             // Firefox is currently the only browser to implement this.
-            return None;
+            return DOMString::new();
         }
         let addr = node.to_trusted_node_address();
         window_from_node(&*self.owner).resolved_style_query(addr, self.pseudo.clone(), property)
@@ -103,14 +102,7 @@ impl CSSStyleDeclarationMethods for CSSStyleDeclaration {
     }
 
     // https://dev.w3.org/csswg/cssom/#dom-cssstyledeclaration-getpropertyvalue
-    fn GetPropertyValue(&self, mut property: DOMString) -> DOMString {
-        if self.readonly {
-            // Readonly style declarations are used for getComputedStyle.
-            property.make_ascii_lowercase();
-            let property = Atom::from(property);
-            return self.get_computed_style(&property).unwrap_or(DOMString::new());
-        }
-
+    fn GetPropertyValue(&self, property: DOMString) -> DOMString {
         let id = if let Ok(id) = PropertyId::parse(property.into()) {
             id
         } else {
@@ -118,6 +110,11 @@ impl CSSStyleDeclarationMethods for CSSStyleDeclaration {
             return DOMString::new()
         };
 
+        if self.readonly {
+            // Readonly style declarations are used for getComputedStyle.
+            return self.get_computed_style(id);
+        }
+
         let style_attribute = self.owner.style_attribute().borrow();
         let style_attribute = if let Some(ref lock) = *style_attribute {
             lock.read()
diff --git a/components/script/dom/window.rs b/components/script/dom/window.rs
index 282979dc7bf..db6490b41fd 100644
--- a/components/script/dom/window.rs
+++ b/components/script/dom/window.rs
@@ -92,6 +92,7 @@ use std::sync::mpsc::TryRecvError::{Disconnected, Empty};
 use style::context::ReflowGoal;
 use style::error_reporting::ParseErrorReporter;
 use style::media_queries;
+use style::properties::PropertyId;
 use style::properties::longhands::overflow_x;
 use style::selector_parser::PseudoElement;
 use style::str::HTML_SPACE_CHARACTERS;
@@ -1295,16 +1296,16 @@ impl Window {
     }
 
     pub fn resolved_style_query(&self,
-                            element: TrustedNodeAddress,
-                            pseudo: Option<PseudoElement>,
-                            property: &Atom) -> Option<DOMString> {
+                                element: TrustedNodeAddress,
+                                pseudo: Option<PseudoElement>,
+                                property: PropertyId) -> DOMString {
         if !self.reflow(ReflowGoal::ForScriptQuery,
-                        ReflowQueryType::ResolvedStyleQuery(element, pseudo, property.clone()),
+                        ReflowQueryType::ResolvedStyleQuery(element, pseudo, property),
                         ReflowReason::Query) {
-            return None;
+            return DOMString::new();
         }
         let ResolvedStyleResponse(resolved) = self.layout_rpc.resolved_style();
-        resolved.map(DOMString::from)
+        DOMString::from(resolved)
     }
 
     pub fn offset_parent_query(&self, node: TrustedNodeAddress) -> (Option<Root<Element>>, Rect<Au>) {