Have Node::document() return a reference instead of a pointer

Source/core/dom/EventRetargeter.cpp

Index: Source/core/dom/EventRetargeter.cpp
diff --git a/Source/core/dom/EventRetargeter.cpp b/Source/core/dom/EventRetargeter.cpp
index cf2d449353e8a3133f825b4ccafe49f13ffab32e..905262efd47fd5de7de90599aaeace0574eea10e 100644
--- a/Source/core/dom/EventRetargeter.cpp
+++ b/Source/core/dom/EventRetargeter.cpp
@@ -47,7 +47,7 @@ static inline EventDispatchBehavior determineDispatchBehavior(Event* event, Shad
 {
     // Video-only full screen is a mode where we use the shadow DOM as an implementation
     // detail that should not be detectable by the web content.
-    if (Element* element = FullscreenElementStack::currentFullScreenElementFrom(target->toNode()->document())) {
+    if (Element* element = FullscreenElementStack::currentFullScreenElementFrom(&target->toNode()->document())) {
         // FIXME: We assume that if the full screen element is a media element that it's
         // the video-only full screen. Both here and elsewhere. But that is probably wrong.
         if (element->isMediaElement() && shadowRoot && shadowRoot->host() == element)