Rename Caret.{h,cpp} to CaretBase to match class.

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 10 matching lines @@
  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef FrameSelection_h
 #define FrameSelection_h
 
 #include "core/CoreExport.h"
 #include "core/dom/Range.h"
-#include "core/editing/Caret.h"
+#include "core/editing/CaretBase.h"
 #include "core/editing/EditingStyle.h"
 #include "core/editing/EphemeralRange.h"
 #include "core/editing/VisiblePosition.h"
 #include "core/editing/VisibleSelection.h"
 #include "core/layout/ScrollAlignment.h"
 #include "platform/Timer.h"
 #include "platform/geometry/IntRect.h"
 #include "platform/geometry/LayoutRect.h"
 #include "platform/heap/Handle.h"
 #include "wtf/Noncopyable.h"
@@ skipping 295 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