[Experiment] DCHECK clean layout tree in mostForward/BackwardCaretPosition

third_party/WebKit/Source/core/editing/FrameSelection.cpp

 /*
  * Copyright (C) 2004, 2008, 2009, 2010 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 60 matching lines @@
 #include "core/page/EditorClient.h"
 #include "core/page/FocusController.h"
 #include "core/page/FrameTree.h"
 #include "core/page/Page.h"
 #include "core/page/SpatialNavigation.h"
 #include "core/paint/PaintLayer.h"
 #include "platform/SecureTextInput.h"
 #include "platform/geometry/FloatQuad.h"
 #include "platform/graphics/GraphicsContext.h"
 #include "platform/text/UnicodeUtilities.h"
+#include "wtf/AutoReset.h"
 #include "wtf/PtrUtil.h"
 #include "wtf/text/CString.h"
 #include <stdio.h>
 
 #define EDIT_DEBUG 0
 
 namespace blink {
 
 using namespace HTMLNames;
 
@@ skipping 492 matching lines @@
       updatePostionAfterAdoptingTextNodeSplit(selection().start(), oldNode);
   Position end =
       updatePostionAfterAdoptingTextNodeSplit(selection().end(), oldNode);
   updateSelectionIfNeeded(base, extent, start, end);
 }
 
 void FrameSelection::updateSelectionIfNeeded(const Position& base,
                                              const Position& extent,
                                              const Position& start,
                                              const Position& end) {
+  AutoReset<bool> scope(&m_inUpdateSelectionIfNeeded, true);
+
   if (base == selection().base() && extent == selection().extent() &&
       start == selection().start() && end == selection().end())
     return;
   // TODO(yosin): We should move to call |TypingCommand::closeTyping()| to
   // |Editor| class.
   if (!document().isRunningExecCommand())
     TypingCommand::closeTyping(m_frame);
   VisibleSelection newSelection;
   if (selection().isBaseFirst())
     newSelection.setWithoutValidation(start, end);
@@ skipping 802 matching lines @@
 }
 
 void showTree(const blink::FrameSelection* sel) {
   if (sel)
     sel->showTreeForThis();
   else
     LOG(INFO) << "Cannot showTree for <null> FrameSelection.";
 }
 
 #endif