Bug 1456588 part 6. Change nsXULCommandDispatcher::GetRootFocusedContentAndWindow to return Element. r=enndeakin

dom/xul/nsXULCommandDispatcher.cpp

@@ -99,7 +99,7 @@ nsXULCommandDispatcher::GetWindowRoot()
   return nullptr;
 }
 
-nsIContent*
+Element*
 nsXULCommandDispatcher::GetRootFocusedContentAndWindow(nsPIDOMWindowOuter** aWindow)
 {
   *aWindow = nullptr;
@@ -126,22 +126,20 @@ nsXULCommandDispatcher::GetFocusedElement(Element** aElement)
   *aElement = nullptr;
 
   nsCOMPtr<nsPIDOMWindowOuter> focusedWindow;
-  nsIContent* focusedContent =
+  RefPtr<Element> focusedContent =
     GetRootFocusedContentAndWindow(getter_AddRefs(focusedWindow));
   if (focusedContent) {
-    CallQueryInterface(focusedContent, aElement);
-
     // Make sure the caller can access the focused element.
-    nsINode* node = *aElement;
-    if (!node || !nsContentUtils::SubjectPrincipalOrSystemIfNativeCaller()->Subsumes(node->NodePrincipal())) {
+    if (!nsContentUtils::SubjectPrincipalOrSystemIfNativeCaller()->
+          Subsumes(focusedContent->NodePrincipal())) {
       // XXX This might want to return null, but we use that return value
       // to mean "there is no focused element," so to be clear, throw an
       // exception.
-      NS_RELEASE(*aElement);
       return NS_ERROR_DOM_SECURITY_ERR;
     }
   }
 
+  focusedContent.forget(aElement);
   return NS_OK;
 }
 

dom/xul/nsXULCommandDispatcher.h

@@ -23,6 +23,12 @@
 class nsIDOMElement;
 class nsPIWindowRoot;
 
+namespace mozilla {
+namespace dom {
+class Element;
+} // namespace dom
+} // namespace mozilla
+
 class nsXULCommandDispatcher : public nsIDOMXULCommandDispatcher,
                                public nsSupportsWeakReference
 {
@@ -43,7 +49,8 @@ protected:
 
     already_AddRefed<nsPIWindowRoot> GetWindowRoot();
 
-    nsIContent* GetRootFocusedContentAndWindow(nsPIDOMWindowOuter** aWindow);
+    mozilla::dom::Element*
+      GetRootFocusedContentAndWindow(nsPIDOMWindowOuter** aWindow);
 
     nsCOMPtr<nsIDocument> mDocument;