Auto merge of #25629 - pshaughn:reflect_translate, r=jdm

Implement "translate" attribute

This attribute is almost a straightforward enumerated one, but the getter value inherits from parents when the content attribute is absent, even when the parents are non-HTML elements. This initial commit is using LocalName::from on a static string; once html5ever has a release with "translate" in the built-in local name list, a small change will be needed.

---
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- [X] These changes fix #25628

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1 files changed, 19 insertions, 0 deletions

diff --git a/components/script/dom/element.rs b/components/script/dom/element.rs
index c26e492d544..3c321d83f54 100644
--- a/components/script/dom/element.rs
+++ b/components/script/dom/element.rs
@@ -523,6 +523,25 @@ impl Element {
             debug_assert!(false, "Trying to detach a non-attached shadow root");
         }
     }
+
+    // https://html.spec.whatwg.org/multipage/#translation-mode
+    pub fn is_translate_enabled(&self) -> bool {
+        // TODO change this to local_name! when html5ever updates
+        let name = &LocalName::from("translate");
+        if self.has_attribute(name) {
+            match &*self.get_string_attribute(name) {
+                "yes" | "" => return true,
+                "no" => return false,
+                _ => {},
+            }
+        }
+        if let Some(parent) = self.upcast::<Node>().GetParentNode() {
+            if let Some(elem) = parent.downcast::<Element>() {
+                return elem.is_translate_enabled();
+            }
+        }
+        true // whatwg/html#5239
+    }
 }
 
 #[allow(unsafe_code)]