ImportLoader* ImportManager::GetNearestPredecessor(nsINode* aNode)
{
  // Return the previous link if there is any in the same document.
  nsIDocument* doc = aNode->OwnerDoc();
  int32_t idx = doc->IndexOfSubImportLink(aNode);
  MOZ_ASSERT(idx != -1, "aNode must be a sub import link of its owner document");

  for (; idx > 0; idx--) {
    HTMLLinkElement* link =
      static_cast<HTMLLinkElement*>(doc->GetSubImportLink(idx - 1));
    nsCOMPtr<nsIURI> uri = link->GetHrefURI();
    RefPtr<ImportLoader> ret;
    mImports.Get(uri, getter_AddRefs(ret));
    // Only main referrer links are interesting.
    if (ret->GetMainReferrer() == link) {
      return ret;
    }
  }

  if (idx == 0) {
    if (doc->IsMasterDocument()) {
      // If there is no previous one, and it was the master document, then
      // there is no predecessor.
      return nullptr;
    }
    // Else we find the main referrer of the import parent of the link's document.
    // And do a recursion.
    ImportLoader* owner = Find(doc);
    MOZ_ASSERT(owner);
    nsCOMPtr<nsINode> mainReferrer = owner->GetMainReferrer();
    return GetNearestPredecessor(mainReferrer);
  }

  return nullptr;
}
ImportLoader*
ImportManager::Find(nsINode* aLink)
{
  HTMLLinkElement* linkElement = static_cast<HTMLLinkElement*>(aLink);
  nsCOMPtr<nsIURI> uri = linkElement->GetHrefURI();
  return mImports.GetWeak(uri);
}