Merge two IsInDocument implementations.

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

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/input/EventHandlingUtil.h"
 
 #include "core/frame/FrameView.h"
 #include "core/frame/LocalFrame.h"
 #include "core/layout/api/LayoutViewItem.h"
 #include "core/paint/PaintLayer.h"
@@ skipping 65 matching lines @@
   if (!layout_object)
     return nullptr;
 
   PaintLayer* layer = layout_object->EnclosingLayer();
   if (!layer)
     return nullptr;
 
   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())
       return scrollable_area;
   }
 
   return nullptr;
 }
 
 ContainerNode* ParentForClickEvent(const Node& node) {
@@ skipping 23 matching lines @@
 
   return frame->GetDocument()->PerformMouseEventHitTest(
       request,
       ContentPointFromRootFrame(frame,
                                 FlooredIntPoint(mev.PositionInRootFrame())),
       mev);
 }
 
 }  // namespace EventHandlingUtil
 }  // namespace blink