Bug 1555947 - Be consistent in using composed / uncomposed doc for <link rel=localization>. r=smaug

Differential Revision: https://phabricator.services.mozilla.com/D49180

--HG--
extra : moz-landing-system : lando

dom/html/HTMLLinkElement.cpp

@@ -137,8 +137,6 @@ nsresult HTMLLinkElement::BindToTree(BindContext& aContext, nsINode& aParent) {
   nsContentUtils::AddScriptRunner(
       NewRunnableMethod("dom::HTMLLinkElement::BindToTree", this, update));
 
-  // FIXME(emilio, bug 1555947): Why does this use the uncomposed doc but the
-  // attribute change code the composed doc?
   if (IsInUncomposedDoc() &&
       AttrValueIs(kNameSpaceID_None, nsGkAtoms::rel, nsGkAtoms::localization,
                   eIgnoreCase)) {
@@ -175,13 +173,12 @@ void HTMLLinkElement::UnbindFromTree(bool aNullParent) {
   Document* oldDoc = GetUncomposedDoc();
   ShadowRoot* oldShadowRoot = GetContainingShadow();
 
-  // We want to update the localization but only if the
-  // link is removed from a DOM change, and not
-  // because the document is going away.
+  // We want to update the localization but only if the link is removed from a
+  // DOM change, and not because the document is going away.
   bool ignore;
   if (oldDoc && oldDoc->GetScriptHandlingObject(ignore) &&
-      this->AttrValueIs(kNameSpaceID_None, nsGkAtoms::rel,
-                        nsGkAtoms::localization, eIgnoreCase)) {
+      AttrValueIs(kNameSpaceID_None, nsGkAtoms::rel, nsGkAtoms::localization,
+                  eIgnoreCase)) {
     oldDoc->LocalizationLinkRemoved(this);
   }
 
@@ -288,8 +285,7 @@ nsresult HTMLLinkElement::AfterSetAttr(int32_t aNameSpaceID, nsAtom* aName,
   // If a link's `rel` attribute was changed from or to `localization`,
   // update the list of localization links.
   if (aNameSpaceID == kNameSpaceID_None && aName == nsGkAtoms::rel) {
-    Document* doc = GetComposedDoc();
-    if (doc) {
+    if (Document* doc = GetUncomposedDoc()) {
       if ((aValue && aValue->Equals(nsGkAtoms::localization, eIgnoreCase)) &&
           (!aOldValue ||
            !aOldValue->Equals(nsGkAtoms::localization, eIgnoreCase))) {
@@ -308,8 +304,7 @@ nsresult HTMLLinkElement::AfterSetAttr(int32_t aNameSpaceID, nsAtom* aName,
   if (aNameSpaceID == kNameSpaceID_None && aName == nsGkAtoms::href &&
       AttrValueIs(kNameSpaceID_None, nsGkAtoms::rel, nsGkAtoms::localization,
                   eIgnoreCase)) {
-    Document* doc = GetComposedDoc();
-    if (doc) {
+    if (Document* doc = GetUncomposedDoc()) {
       if (aOldValue) {
         doc->LocalizationLinkRemoved(this);
       }