Introduce composed tree version of VisiblePosition

Source/core/editing/SelectionController.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2012 Digia Plc. and/or its subsidiary(-ies)
  * Copyright (C) 2015 Google 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
@@ skipping 137 matching lines @@
     // existing selection so we can allow for text dragging.
     if (FrameView* view = m_frame->view()) {
         LayoutPoint vPoint = view->rootFrameToContents(event.event().position());
         if (!extendSelection && selection().contains(vPoint)) {
             m_mouseDownWasSingleClickInSelection = true;
             return false;
         }
     }
 
     PositionWithAffinity eventPos = innerNode->layoutObject()->positionForPoint(event.localPoint());
-    VisiblePosition visiblePos = createVisiblePosition(Strategy::toPositionType(eventPos.position()), eventPos.affinity());
+    VisiblePosition visiblePos = createVisiblePositionInDOMTree(Strategy::toPositionType(eventPos.position()), eventPos.affinity());
     if (visiblePos.isNull())
         visiblePos = createVisiblePosition(firstPositionInOrBeforeNode(innerNode));
     PositionType pos = Strategy::toPositionType(visiblePos.deepEquivalent());
 
     VisibleSelection newSelection = selection().selection();
     TextGranularity granularity = CharacterGranularity;
 
     if (extendSelection && newSelection.isCaretOrRange()) {
-        VisibleSelection selectionInUserSelectAll(expandSelectionToRespectUserSelectAll(innerNode, VisibleSelection(createVisiblePosition(pos))));
+        VisibleSelection selectionInUserSelectAll(expandSelectionToRespectUserSelectAll(innerNode, VisibleSelection(createVisiblePositionInDOMTree(pos))));
         if (selectionInUserSelectAll.isRange()) {
             if (Strategy::selectionStart(selectionInUserSelectAll).compareTo(Strategy::selectionStart(newSelection)) < 0)
                 pos = Strategy::selectionStart(selectionInUserSelectAll);
             else if (Strategy::selectionEnd(newSelection).compareTo(Strategy::selectionEnd(selectionInUserSelectAll)) < 0)
                 pos = Strategy::selectionEnd(selectionInUserSelectAll);
         }
 
         if (!m_frame->editor().behavior().shouldConsiderSelectionAsDirectional()) {
             if (pos.isNotNull()) {
                 // See <rdar://problem/3668157> REGRESSION (Mail): shift-click deselects when selection
@@ skipping 30 matching lines @@
     using PositionType = typename Strategy::PositionType;
 
     if (!m_mouseDownMayStartSelect)
         return;
 
     Node* target = hitTestResult.innerNode();
     if (!target)
         return;
 
     PositionWithAffinity rawTargetPosition = selection().selection().positionRespectingEditingBoundary(hitTestResult.localPoint(), target);
-    VisiblePosition targetPosition = createVisiblePosition(Strategy::toPositionType(rawTargetPosition.position()), rawTargetPosition.affinity());
+    VisiblePosition targetPosition = createVisiblePositionInDOMTree(Strategy::toPositionType(rawTargetPosition.position()), rawTargetPosition.affinity());
     // Don't modify the selection if we're not on a node.
     if (targetPosition.isNull())
         return;
 
     // Restart the selection if this is the first mouse move. This work is usually
     // done in handleMousePressEvent, but not if the mouse press was on an existing selection.
     VisibleSelection newSelection = selection().selection();
 
     // Special case to limit selection to the containing block for SVG text.
     // FIXME: Isn't there a better non-SVG-specific way to do this?
@@ skipping 421 matching lines @@
     else
         m_selectionState = SelectionState::HaveNotStartedSelection;
 }
 
 FrameSelection& SelectionController::selection() const
 {
     return m_frame->selection();
 }
 
 } // namespace blink