Use const ref for LocalFrame::LocalFrameRoot and FrameTree::Top

third_party/WebKit/Source/core/layout/LayoutFrame.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Simon Hausmann <hausmann@kde.org>
  *           (C) 2000 Stefan Schimanski (1Stein@gmx.de)
  * Copyright (C) 2004, 2005, 2006, 2009 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 31 matching lines @@
 
 void LayoutFrame::ImageChanged(WrappedImagePtr image, const IntRect*) {
   if (const CursorList* cursors = Style()->Cursors()) {
     for (const CursorData& cursor : *cursors) {
       if (cursor.GetImage() && cursor.GetImage()->CachedImage() == image) {
         if (LocalFrame* frame = this->GetFrame()) {
           // Cursor update scheduling is done by the local root, which is the
           // main frame if there are no RemoteFrame ancestors in the frame tree.
           // Use of localFrameRoot() is discouraged but will change when cursor
           // update scheduling is moved from EventHandler to PageEventHandler.
-          frame->LocalFrameRoot()->GetEventHandler().ScheduleCursorUpdate();
+          frame->LocalFrameRoot().GetEventHandler().ScheduleCursorUpdate();
         }
       }
     }
   }
 }
 
 void LayoutFrame::UpdateFromElement() {
   if (Parent() && Parent()->IsFrameSet())
     ToLayoutFrameSet(Parent())->NotifyFrameEdgeInfoChanged();
 }
 
 }  // namespace blink