Invalidate the previous caret even if the parent text node is removed.

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

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 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 282 matching lines @@
     RawPtrWillBeMember<LocalFrame> m_frame;
     const OwnPtrWillBeMember<PendingSelection> m_pendingSelection;
     const OwnPtrWillBeMember<SelectionEditor> m_selectionEditor;
 
     // Used to store base before the adjustment at bidi boundary
     VisiblePosition m_originalBase;
     VisiblePositionInComposedTree m_originalBaseInComposedTree;
     TextGranularity m_granularity;
 
     RefPtrWillBeMember<Node> m_previousCaretNode; // The last node which painted the caret. Retained for clearing the old caret when it moves.
+    RawPtrWillBeWeakMember<Node> m_parentOfPreviousCaretNode;
     LayoutRect m_previousCaretRect;
     CaretVisibility m_previousCaretVisibility;
 
     RefPtrWillBeMember<EditingStyle> m_typingStyle;
 
     Timer<FrameSelection> m_caretBlinkTimer;
 
     bool m_caretRectDirty : 1;
     bool m_shouldPaintCaret : 1;
     bool m_isCaretBlinkingSuspended : 1;
@@ skipping 20 matching lines @@
 }
 } // namespace blink
 
 #ifndef NDEBUG
 // Outside the WebCore namespace for ease of invocation from gdb.
 void showTree(const blink::FrameSelection&);
 void showTree(const blink::FrameSelection*);
 #endif
 
 #endif // FrameSelection_h