Remove unnecessary inclusions of LayoutObject-derived headers in core/editing/

third_party/WebKit/Source/core/editing/PositionIterator.h

 /*
  * Copyright (C) 2007, 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 12 matching lines @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef PositionIterator_h
 #define PositionIterator_h
 
 #include "core/dom/Node.h"
 #include "core/editing/EditingStrategy.h"
 #include "core/editing/EditingUtilities.h"
 #include "core/html/HTMLHtmlElement.h"
-#include "core/layout/LayoutBlock.h"
 
 namespace blink {
 
 // A Position iterator with nearly constant-time
 // increment, decrement, and several predicates on the Position it is at.
 // Conversion from Position is O(n) in the depth.
 // Conversion to Position is O(1).
 // PositionIteratorAlgorithm must be used without DOM tree change.
 template <typename Strategy>
 class PositionIteratorAlgorithm {
@@ skipping 43 matching lines @@
 
 extern template class PositionIteratorAlgorithm<EditingStrategy>;
 extern template class PositionIteratorAlgorithm<EditingInFlatTreeStrategy>;
 
 using PositionIterator = PositionIteratorAlgorithm<EditingStrategy>;
 using PositionIteratorInFlatTree = PositionIteratorAlgorithm<EditingInFlatTreeStrategy>;
 
 } // namespace blink
 
 #endif // PositionIterator_h