Bug 1253476 - Move IsRendered to Element; r=emilio

And update the GitHub issue link at the same time since #3947 was duped to
#1837.

Differential Revision: https://phabricator.services.mozilla.com/D30326

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

dom/base/Element.h

@@ -1407,6 +1407,14 @@ class Element : public FragmentOrElement {
     return HasServoData() && Servo_Element_IsDisplayContents(this);
   }
 
+  /*
+   * https://html.spec.whatwg.org/#being-rendered
+   *
+   * With a gotcha for display contents:
+   *   https://github.com/whatwg/html/issues/1837
+   */
+  bool IsRendered() const { return GetPrimaryFrame() || IsDisplayContents(); }
+
   const nsAttrValue* GetParsedAttr(const nsAtom* aAttr) const {
     return mAttrs.GetAttr(aAttr);
   }

dom/html/nsGenericHTMLElement.cpp

@@ -2653,14 +2653,6 @@ nsresult nsGenericHTMLElement::NewURIFromString(const nsAString& aURISpec,
   return NS_OK;
 }
 
-// https://html.spec.whatwg.org/#being-rendered
-//
-// With a gotcha for display contents:
-//   https://github.com/whatwg/html/issues/3947
-static bool IsRendered(const Element& aElement) {
-  return aElement.GetPrimaryFrame() || aElement.IsDisplayContents();
-}
-
 void nsGenericHTMLElement::GetInnerText(mozilla::dom::DOMString& aValue,
                                         mozilla::ErrorResult& aError) {
   // innerText depends on layout. For example, white space processing is
@@ -2715,7 +2707,7 @@ void nsGenericHTMLElement::GetInnerText(mozilla::dom::DOMString& aValue,
     doc->FlushPendingNotifications(FlushType::Layout);
   }
 
-  if (!IsRendered(*this)) {
+  if (!IsRendered()) {
     GetTextContentInternal(aValue, aError);
   } else {
     nsRange::GetInnerTextNoFlush(aValue, aError, this);