Merge two IsInDocument implementations.

third_party/WebKit/Source/core/input/EventHandlingUtil.cpp

Index: third_party/WebKit/Source/core/input/EventHandlingUtil.cpp
diff --git a/third_party/WebKit/Source/core/input/EventHandlingUtil.cpp b/third_party/WebKit/Source/core/input/EventHandlingUtil.cpp
index 8ce9d0cac29983c8d1b672e86243e670d4b616e1..cd4ac074a8b175c9f163cd9cb944b5b7e64de248 100644
--- a/third_party/WebKit/Source/core/input/EventHandlingUtil.cpp
+++ b/third_party/WebKit/Source/core/input/EventHandlingUtil.cpp
@@ -83,6 +83,10 @@ PaintLayer* LayerForNode(Node* node) {
   return layer;
 }
 
+bool IsInDocument(EventTarget* n) {
+  return n && n->ToNode() && n->ToNode()->isConnected();
+}
+
 ScrollableArea* AssociatedScrollableArea(const PaintLayer* layer) {
   if (PaintLayerScrollableArea* scrollable_area = layer->GetScrollableArea()) {
     if (scrollable_area->ScrollsOverflow())