Implement Document::cookie correctly for cookie-averse documents.

components/script/dom/document.rs

@@ -1466,6 +1466,19 @@ impl Document {
         let target = node.upcast();
         event.fire(target);
     }
+
+    /// https://html.spec.whatwg.org/multipage/#cookie-averse-document-object
+    fn is_cookie_averse(&self) -> bool {
+        /// https://url.spec.whatwg.org/#network-scheme
+        fn url_has_network_scheme(url: &Url) -> bool {
+            match &*url.scheme {
+                "ftp" | "http" | "https" => true,
+                _ => false,
+            }
+        }
+
+        self.browsing_context.is_none() || !url_has_network_scheme(&self.url)
+    }
 }
 
 #[derive(PartialEq, HeapSizeOf)]
@@ -2390,7 +2403,10 @@ impl DocumentMethods for Document {
 
     // https://html.spec.whatwg.org/multipage/#dom-document-cookie
     fn GetCookie(&self) -> Fallible<DOMString> {
-        // TODO: return empty string for cookie-averse Document
+        if self.is_cookie_averse() {
+            return Ok(DOMString::new());
+        }
+
         let url = self.url();
         if !is_scheme_host_port_tuple(&url) {
             return Err(Error::Security);
@@ -2403,7 +2419,10 @@ impl DocumentMethods for Document {
 
     // https://html.spec.whatwg.org/multipage/#dom-document-cookie
     fn SetCookie(&self, cookie: DOMString) -> ErrorResult {
-        // TODO: ignore for cookie-averse Document
+        if self.is_cookie_averse() {
+            return Ok(());
+        }
+
         let url = self.url();
         if !is_scheme_host_port_tuple(url) {
             return Err(Error::Security);

tests/wpt/metadata/html/dom/documents/resource-metadata-management/document-cookie.html.ini

@@ -1,5 +0,0 @@
-[document-cookie.html]
-  type: testharness
-  [getting cookie for a cookie-averse document returns empty string, setting does nothing]
-    expected: FAIL
-