Make FrameCaret contains CaretBase instead of deriving from it

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 88 matching lines @@
       m_granularity(CharacterGranularity),
       m_xPosForVerticalArrowNavigation(NoXPosForVerticalArrowNavigation()),
       m_focused(frame.page() &&
                 frame.page()->focusController().focusedFrame() == frame),
       m_frameCaret(new FrameCaret(frame, *m_selectionEditor)) {}
 
 FrameSelection::~FrameSelection() {}
 
 const DisplayItemClient& FrameSelection::caretDisplayItemClientForTesting()
     const {
-  return *m_frameCaret;
+  return m_frameCaret->displayItemClient();
 }
 
 const Document& FrameSelection::document() const {
   DCHECK(m_document);
   return *m_document;
 }
 
 Document& FrameSelection::document() {
   DCHECK(m_document);
   return *m_document;
@@ skipping 1290 matching lines @@
 }
 
 void showTree(const blink::FrameSelection* sel) {
   if (sel)
     sel->showTreeForThis();
   else
     LOG(INFO) << "Cannot showTree for <null> FrameSelection.";
 }
 
 #endif