1 files changed, 8 insertions, 0 deletions
diff --git a/dom/webidl/AnonymousContent.webidl b/dom/webidl/AnonymousContent.webidl
index 6755fe598..8be69cd26 100644
--- a/dom/webidl/AnonymousContent.webidl
+++ b/dom/webidl/AnonymousContent.webidl
@@ -77,4 +77,12 @@ interface AnonymousContent {
   [Throws]
   void setCutoutRectsForElement(DOMString elementId,
                                 sequence<DOMRect> rects);
+
+  /**
+   * Get the computed value of a property on an element inside this custom
+   * anonymous content.
+   */
+  [Throws]
+  DOMString? getComputedStylePropertyValue(DOMString elementId,
+                                           DOMString propertyName);
 };