Bug 1635082 - Remove nsImageLoadingContent::GetImageReferrerPolicy. r=edgar

It's useless now, the relevant check lives in
ReferrerInfo::InitFromNode.

Differential Revision: https://phabricator.services.mozilla.com/D73620

dom/base/nsImageLoadingContent.cpp

@@ -1797,12 +1797,6 @@ bool nsImageLoadingContent::ScriptedImageObserver::CancelRequests() {
   return cancelled;
 }
 
-// Only HTMLInputElement.h overrides this for <img> tags
-// all other subclasses use this one, i.e. ignore referrer attributes
-mozilla::dom::ReferrerPolicy nsImageLoadingContent::GetImageReferrerPolicy() {
-  return mozilla::dom::ReferrerPolicy::_empty;
-}
-
 Element* nsImageLoadingContent::FindImageMap() {
   nsIContent* thisContent = AsContent();
   Element* thisElement = thisContent->AsElement();

dom/base/nsImageLoadingContent.h

@@ -213,8 +213,6 @@ class nsImageLoadingContent : public nsIImageLoadingContent {
    */
   virtual mozilla::CORSMode GetCORSMode();
 
-  virtual mozilla::dom::ReferrerPolicy GetImageReferrerPolicy();
-
   // Subclasses are *required* to call BindToTree/UnbindFromTree.
   void BindToTree(mozilla::dom::BindContext&, nsINode& aParent);
   void UnbindFromTree(bool aNullParent);

dom/html/HTMLImageElement.cpp

@@ -393,7 +393,7 @@ nsresult HTMLImageElement::AfterSetAttr(int32_t aNameSpaceID, nsAtom* aName,
         aValue && static_cast<ImageDecodingType>(aValue->GetEnumValue()) ==
                       ImageDecodingType::Sync);
   } else if (aName == nsGkAtoms::referrerpolicy) {
-    ReferrerPolicy referrerPolicy = GetImageReferrerPolicy();
+    ReferrerPolicy referrerPolicy = GetReferrerPolicyAsEnum();
     // FIXME(emilio): Why only  when not in responsive mode? Also see below for
     // aNotify.
     forceReload = aNotify && !InResponsiveMode() &&

dom/html/HTMLImageElement.h

@@ -203,10 +203,6 @@ class HTMLImageElement final : public nsGenericHTMLElement,
 
   already_AddRefed<Promise> Decode(ErrorResult& aRv);
 
-  ReferrerPolicy GetImageReferrerPolicy() override {
-    return GetReferrerPolicyAsEnum();
-  }
-
   MOZ_CAN_RUN_SCRIPT int32_t X();
   MOZ_CAN_RUN_SCRIPT int32_t Y();
   void GetLowsrc(nsAString& aLowsrc) {