Introduce composed tree version of inSameLine()

Source/core/editing/VisibleUnits.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 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 1103 matching lines @@
 bool inSameLine(const PositionInComposedTreeWithAffinity& position1, const PositionInComposedTreeWithAffinity& position2)
 {
     return inSameLineAlgorithm<EditingInComposedTreeStrategy>(position1, position2);
 }
 
 bool inSameLine(const VisiblePosition& position1, const VisiblePosition& position2)
 {
     return inSameLine(position1.toPositionWithAffinity(), position2.toPositionWithAffinity());
 }
 
+bool inSameLine(const VisiblePositionInComposedTree& position1, const VisiblePositionInComposedTree& position2)
+{
+    return inSameLine(position1.toPositionWithAffinity(), position2.toPositionWithAffinity());
+}
+
 bool isStartOfLine(const VisiblePosition& p)
 {
     return p.isNotNull() && p.deepEquivalent() == startOfLine(p).deepEquivalent();
 }
 
 bool isEndOfLine(const VisiblePosition& p)
 {
     return p.isNotNull() && p.deepEquivalent() == endOfLine(p).deepEquivalent();
 }
 
@@ skipping 1818 matching lines @@
         return honorEditingBoundaryAtOrBefore(prev, visiblePosition.deepEquivalent());
     case CanSkipOverEditingBoundary:
         return skipToStartOfEditingBoundary(prev, visiblePosition.deepEquivalent());
     }
 
     ASSERT_NOT_REACHED();
     return honorEditingBoundaryAtOrBefore(prev, visiblePosition.deepEquivalent());
 }
 
 } // namespace blink