Get rid of flat tree version of createVisibleSelection() taking two VisiblePosition

third_party/WebKit/Source/core/editing/commands/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 179 matching lines @@
 void DeleteSelectionCommand::setStartingSelectionOnSmartDelete(
     const Position& start,
     const Position& end) {
   DCHECK(!document().needsLayoutTreeUpdate());
   DocumentLifecycle::DisallowTransitionScope disallowTransition(
       document().lifecycle());
 
   bool isBaseFirst = startingSelection().isBaseFirst();
   VisiblePosition newBase = createVisiblePosition(isBaseFirst ? start : end);
   VisiblePosition newExtent = createVisiblePosition(isBaseFirst ? end : start);
-  setStartingSelection(createVisibleSelection(
-      newBase, newExtent, startingSelection().isDirectional()));
+  SelectionInDOMTree::Builder builder;
+  builder.setIsDirectional(startingSelection().isDirectional());
+  if (newBase.isNotNull() && newExtent.isNotNull()) {

[Xiaocheng, 2016/10/21 11:18:36]

Let's use setBaseAndExtentDeprecated, as having a null VP here might indicate
something going wrong.

[yosin_UTC9, 2016/10/24 06:19:44]

Done.

+    builder.collapse(newBase.deepEquivalent())
+        .extend(newExtent.deepEquivalent());
+  } else if (newBase.isNotNull()) {
+    builder.collapse(newBase.deepEquivalent());
+  } else if (newExtent.isNotNull()) {
+    builder.collapse(newExtent.deepEquivalent());
+  }
+  setStartingSelection(createVisibleSelection(builder.build()));
 }
 
 void DeleteSelectionCommand::initializePositionData(
     EditingState* editingState) {
   DCHECK(!document().needsLayoutTreeUpdate());
   DocumentLifecycle::DisallowTransitionScope disallowTransition(
       document().lifecycle());
 
   Position start, end;
   initializeStartEnd(start, end);
@@ skipping 998 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 blink