diff --git a/dom/base/nsContentUtils.cpp b/dom/base/nsContentUtils.cpp
index 18721ed6febe..b0a6742ec358 100644
--- a/dom/base/nsContentUtils.cpp
+++ b/dom/base/nsContentUtils.cpp
@@ -2231,20 +2231,6 @@ nsContentUtils::InProlog(nsINode *aNode)
   return !root || doc->ComputeIndexOf(aNode) < doc->ComputeIndexOf(root);
 }
 
-nsIDocument*
-nsContentUtils::GetDocumentFromCaller()
-{
-  AutoJSContext cx;
-
-  nsCOMPtr<nsPIDOMWindowInner> win =
-    do_QueryInterface(nsJSUtils::GetStaticScriptGlobal(JS::CurrentGlobalOrNull(cx)));
-  if (!win) {
-    return nullptr;
-  }
-
-  return win->GetExtantDoc();
-}
-
 bool
 nsContentUtils::IsCallerChrome()
 {
diff --git a/dom/base/nsContentUtils.h b/dom/base/nsContentUtils.h
index 19ab2659e4bf..f17589379d94 100644
--- a/dom/base/nsContentUtils.h
+++ b/dom/base/nsContentUtils.h
@@ -630,18 +630,6 @@ public:
    */
   static bool IsAbsoluteURL(const nsACString& aURL);
 
-  /**
-   * GetDocumentFromCaller gets its document by looking at the last called
-   * function and finding the document that the function itself relates to.
-   * For example, consider two windows A and B in the same origin. B has a
-   * function which does something that ends up needing the current document.
-   * If a script in window A were to call B's function, GetDocumentFromCaller
-   * would find that function (in B) and return B's document.
-   *
-   * @return The document or null if no JS Context.
-   */
-  static nsIDocument* GetDocumentFromCaller();
-
   // Check if a node is in the document prolog, i.e. before the document
   // element.
   static bool InProlog(nsINode *aNode);