diff --git a/dom/xul/XULDocument.cpp b/dom/xul/XULDocument.cpp
index 686a035a18c..fa87020f90e 100644
--- a/dom/xul/XULDocument.cpp
+++ b/dom/xul/XULDocument.cpp
@@ -924,23 +924,6 @@ XULDocument::AttributeWillChange(nsIDocument* aDocument,
     }
 }
 
-static bool
-ShouldPersistAttribute(nsIDocument* aDocument, Element* aElement)
-{
-    if (aElement->IsXULElement(nsGkAtoms::window)) {
-        if (nsCOMPtr<nsPIDOMWindow> window = aDocument->GetWindow()) {
-            bool isFullscreen;
-            window->GetFullScreen(&isFullscreen);
-            if (isFullscreen) {
-                // Don't persist attributes if it is window element and
-                // we are in fullscreen state.
-                return false;
-            }
-        }
-    }
-    return true;
-}
-
 void
 XULDocument::AttributeChanged(nsIDocument* aDocument,
                               Element* aElement, int32_t aNameSpaceID,
@@ -1016,19 +999,18 @@ XULDocument::AttributeChanged(nsIDocument* aDocument,
     bool listener, resolved;
     CheckBroadcasterHookup(aElement, &listener, &resolved);
 
-    if (ShouldPersistAttribute(aDocument, aElement)) {
-        // See if there is anything we need to persist in the localstore.
-        //
-        // XXX Namespace handling broken :-(
-        nsString persist;
-        aElement->GetAttr(kNameSpaceID_None, nsGkAtoms::persist, persist);
-        if (!persist.IsEmpty() &&
-            // XXXldb This should check that it's a token, not just a substring.
-            persist.Find(nsDependentAtomString(aAttribute)) >= 0) {
+    // See if there is anything we need to persist in the localstore.
+    //
+    // XXX Namespace handling broken :-(
+    nsAutoString persist;
+    aElement->GetAttr(kNameSpaceID_None, nsGkAtoms::persist, persist);
+    if (!persist.IsEmpty()) {
+        // XXXldb This should check that it's a token, not just a substring.
+        if (persist.Find(nsDependentAtomString(aAttribute)) >= 0) {
             nsContentUtils::AddScriptRunner(NS_NewRunnableMethodWithArgs
-                <nsIContent*, int32_t, nsIAtom*>
-                (this, &XULDocument::DoPersist, aElement,
-                 kNameSpaceID_None, aAttribute));
+              <nsIContent*, int32_t, nsIAtom*>
+              (this, &XULDocument::DoPersist, aElement, kNameSpaceID_None,
+               aAttribute));
         }
     }
 }
diff --git a/xpfe/appshell/nsXULWindow.cpp b/xpfe/appshell/nsXULWindow.cpp
index 030f37e4ed2..0265860831a 100644
--- a/xpfe/appshell/nsXULWindow.cpp
+++ b/xpfe/appshell/nsXULWindow.cpp
@@ -1436,16 +1436,6 @@ NS_IMETHODIMP nsXULWindow::SavePersistentAttributes()
   if (!mDocShell)
     return NS_ERROR_FAILURE;
 
-  nsCOMPtr<nsIDOMWindow> domWindow;
-  GetWindowDOMWindow(getter_AddRefs(domWindow));
-  if (domWindow) {
-    bool isFullscreen;
-    domWindow->GetFullScreen(&isFullscreen);
-    if (isFullscreen) {
-      return NS_OK;
-    }
-  }
-
   nsCOMPtr<dom::Element> docShellElement = GetWindowDOMElement();
   if (!docShellElement)
     return NS_ERROR_FAILURE;