Rename {first,last}EditablePosition{After,Before}Position... to denote them returned VisiblePosition

Source/core/editing/DeleteSelectionCommand.cpp

 /*
  * Copyright (C) 2005 Apple Computer, 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 148 matching lines @@
     setStartingSelection(VisibleSelection(newBase, newExtent, startingSelection().isDirectional()));
 }
 
 void DeleteSelectionCommand::initializePositionData()
 {
     Position start, end;
     initializeStartEnd(start, end);
 
     ASSERT(isEditablePosition(start, ContentIsEditable, DoNotUpdateStyle));
     if (!isEditablePosition(end, ContentIsEditable, DoNotUpdateStyle))
-        end = lastEditablePositionBeforePositionInRoot(end, highestEditableRoot(start)).deepEquivalent();
+        end = lastEditableVisiblePositionBeforePositionInRoot(end, highestEditableRoot(start)).deepEquivalent();
 
     m_upstreamStart = start.upstream();
     m_downstreamStart = start.downstream();
     m_upstreamEnd = end.upstream();
     m_downstreamEnd = end.downstream();
 
     m_startRoot = editableRootForPosition(start);
     m_endRoot = editableRootForPosition(end);
 
     m_startTableRow = enclosingNodeOfType(start, &isHTMLTableRowElement);
@@ skipping 704 matching lines @@
     visitor->trace(m_deleteIntoBlockquoteStyle);
     visitor->trace(m_startRoot);
     visitor->trace(m_endRoot);
     visitor->trace(m_startTableRow);
     visitor->trace(m_endTableRow);
     visitor->trace(m_temporaryPlaceholder);
     CompositeEditCommand::trace(visitor);
 }
 
 } // namespace WebCore