Move computeInlineBoxPosition() to VisibleUnits.{cpp,h} from Position.{cpp,h} and VisiblePosition.h

Source/core/editing/VisiblePosition.h

 /*
  * Copyright (C) 2004, 2008 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 120 matching lines @@
     template<typename Strategy>
     void init(const PositionAlgorithm<Strategy>&, TextAffinity);
 
     Position leftVisuallyDistinctCandidate() const;
     Position rightVisuallyDistinctCandidate() const;
 
     Position m_deepPosition;
     TextAffinity m_affinity;
 };
 
-// TODO(yosin) We should move |computeInlineBoxPosition()| to "VisibleUnits.h"
-// with |Position| version.
-inline InlineBoxPosition computeInlineBoxPosition(const VisiblePosition& position)
-{
-    return computeInlineBoxPosition(position.deepEquivalent(), position.affinity());
-}
-
 EphemeralRange makeRange(const VisiblePosition&, const VisiblePosition&);
 
 CORE_EXPORT Position canonicalPositionOf(const Position&);
 CORE_EXPORT PositionInComposedTree canonicalPositionOf(const PositionInComposedTree&);
 PositionWithAffinity honorEditingBoundaryAtOrBeforeOf(const PositionWithAffinity&, const Position& anchor);
 PositionInComposedTreeWithAffinity honorEditingBoundaryAtOrBeforeOf(const PositionInComposedTreeWithAffinity&, const PositionInComposedTree& anchor);
 
 } // namespace blink
 
 #ifndef NDEBUG
 // Outside the WebCore namespace for ease of invocation from gdb.
 void showTree(const blink::VisiblePosition*);
 void showTree(const blink::VisiblePosition&);
 #endif
 
 #endif // VisiblePosition_h