Use Position and PositionInComposedTree to create VisiblePosition at SelectionController

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 260 matching lines @@
     // Don't restart the selection when the mouse is pressed on an
     // existing selection so we can allow for text dragging.
     if (FrameView* view = m_frame->view()) {
         LayoutPoint vPoint = view->rootFrameToContents(event.event().position());
         if (!extendSelection && m_frame->selection().contains(vPoint)) {
             m_mouseDownWasSingleClickInSelection = true;
             return false;
         }
     }
 
-    VisiblePosition visiblePos(innerNode->layoutObject()->positionForPoint(event.localPoint()));
+    PositionWithAffinity eventPos = innerNode->layoutObject()->positionForPoint(event.localPoint());
+    VisiblePosition visiblePos(Strategy::toPositionType(eventPos.position()), eventPos.affinity());
     if (visiblePos.isNull())
         visiblePos = VisiblePosition(firstPositionInOrBeforeNode(innerNode), DOWNSTREAM);
     PositionType pos = Strategy::toPositionType(visiblePos.deepEquivalent());
 
     VisibleSelection newSelection = m_frame->selection().selection();
     TextGranularity granularity = CharacterGranularity;
 
     if (extendSelection && newSelection.isCaretOrRange()) {
         VisibleSelection selectionInUserSelectAll(expandSelectionToRespectUserSelectAll(innerNode, VisibleSelection(VisiblePosition(pos))));
         if (selectionInUserSelectAll.isRange()) {
@@ skipping 89 matching lines @@
 {
     using PositionType = typename Strategy::PositionType;
 
     if (!m_mouseDownMayStartSelect)
         return;
 
     Node* target = hitTestResult.innerNode();
     if (!target)
         return;
 
-    VisiblePosition targetPosition = m_frame->selection().selection().visiblePositionRespectingEditingBoundary(hitTestResult.localPoint(), target);
+    PositionWithAffinity rawTargetPosition = m_frame->selection().selection().positionRespectingEditingBoundary(hitTestResult.localPoint(), target);
+    VisiblePosition targetPosition = VisiblePosition(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 = m_frame->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 187 matching lines @@
 {
     return m_mouseDownMayStartSelect;
 }
 
 bool SelectionController::mouseDownWasSingleClickInSelection() const
 {
     return m_mouseDownWasSingleClickInSelection;
 }
 
 } // namespace blink