Get rid of createVisibleSelection() taking two Position

third_party/WebKit/Source/core/editing/commands/CompositeEditCommand.cpp

 /*
  * Copyright (C) 2005, 2006, 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 1421 matching lines @@
           ? start
           : mostBackwardCaretPosition(endOfParagraphToMove.deepEquivalent());
   if (comparePositions(start, end) > 0)
     end = start;
 
   cloneParagraphUnderNewElement(start, end, outerNode, blockElement,
                                 editingState);
 
   document().updateStyleAndLayoutIgnorePendingStylesheets();
 
-  setEndingSelection(createVisibleSelection(start, end));
+  setEndingSelection(createVisibleSelection(
+      SelectionInDOMTree::Builder().collapse(start).extend(end).build()));
   deleteSelection(editingState, false, false, false);
   if (editingState->isAborted())
     return;
 
   // There are bugs in deletion when it removes a fully selected table/list.
   // It expands and removes the entire table/list, but will let content
   // before and after the table/list collapse onto one line.
 
   cleanupAfterDeletion(editingState);
   if (editingState->isAborted())
@@ skipping 138 matching lines @@
     styleInEmptyParagraph->mergeTypingStyle(&document());
     // The moved paragraph should assume the block style of the destination.
     styleInEmptyParagraph->removeBlockProperties();
   }
 
   // FIXME (5098931): We should add a new insert action
   // "WebViewInsertActionMoved" and call shouldInsertFragment here.
 
   DCHECK(!document().needsLayoutTreeUpdate());
 
-  setEndingSelection(createVisibleSelection(start, end));
+  setEndingSelection(createVisibleSelection(
+      SelectionInDOMTree::Builder().collapse(start).extend(end).build()));

[Xiaocheng, 2016/10/26 05:49:18]

Do we have non-null start and end here?

[yosin_UTC9, 2016/10/26 07:43:07]

I would like to know the case which makes start| or |end| as null.

   document()
       .frame()
       ->spellChecker()
       .clearMisspellingsAndBadGrammarForMovingParagraphs(endingSelection());
   deleteSelection(editingState, false, false, false);
   if (editingState->isAborted())
     return;
 
   DCHECK(destination.deepEquivalent().isConnected()) << destination;
   cleanupAfterDeletion(editingState, destination);
@@ skipping 90 matching lines @@
   // to rangeFromLocationAndLength with a location past the end of the
   // document (which will return null).
   EphemeralRange startRange = PlainTextRange(destinationIndex + startIndex)
                                   .createRangeForSelection(*documentElement);
   if (startRange.isNull())
     return;
   EphemeralRange endRange = PlainTextRange(destinationIndex + endIndex)
                                 .createRangeForSelection(*documentElement);
   if (endRange.isNull())
     return;
-  setEndingSelection(createVisibleSelection(
-      startRange.startPosition(), endRange.startPosition(),
-      TextAffinity::Downstream, originalIsDirectional));
+  setEndingSelection(
+      createVisibleSelection(SelectionInDOMTree::Builder()
+                                 .collapse(startRange.startPosition())
+                                 .extend(endRange.startPosition())
+                                 .setIsDirectional(originalIsDirectional)
+                                 .build()));
 }
 
 // FIXME: Send an appropriate shouldDeleteRange call.
 bool CompositeEditCommand::breakOutOfEmptyListItem(EditingState* editingState) {
   DCHECK(!document().needsLayoutTreeUpdate());
   Node* emptyListItem =
       enclosingEmptyListItem(endingSelection().visibleStart());
   if (!emptyListItem)
     return false;
 
@@ skipping 302 matching lines @@
   return node;
 }
 
 DEFINE_TRACE(CompositeEditCommand) {
   visitor->trace(m_commands);
   visitor->trace(m_composition);
   EditCommand::trace(visitor);
 }
 
 }  // namespace blink