Get rid of redundant member function PositionAlgorithm<Strategy>::{upstream,downstream}

Source/core/editing/commands/ReplaceSelectionCommand.cpp

 /*
  * Copyright (C) 2005, 2006, 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2009, 2010, 2011 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
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 1005 matching lines @@
         ASSERT(isHTMLBRElement(br));
         // Insert content between the two blockquotes, but remove the br (since it was just a placeholder).
         insertionPos = positionInParentBeforeNode(*br);
         removeNode(br);
     }
 
     // Inserting content could cause whitespace to collapse, e.g. inserting <div>foo</div> into hello^ world.
     prepareWhitespaceAtPositionForSplit(insertionPos);
 
     // If the downstream node has been removed there's no point in continuing.
-    if (!insertionPos.downstream().anchorNode())
+    if (!mostForwardCaretPosition(insertionPos).anchorNode())
         return;
 
     // NOTE: This would be an incorrect usage of downstream() if downstream() were changed to mean the last position after
     // p that maps to the same visible position as p (since in the case where a br is at the end of a block and collapsed
     // away, there are positions after the br which map to the same visible position as [br, 0]).
-    HTMLBRElement* endBR = isHTMLBRElement(*insertionPos.downstream().anchorNode()) ? toHTMLBRElement(insertionPos.downstream().anchorNode()) : 0;
+    HTMLBRElement* endBR = isHTMLBRElement(*mostForwardCaretPosition(insertionPos).anchorNode()) ? toHTMLBRElement(mostForwardCaretPosition(insertionPos).anchorNode()) : 0;
     VisiblePosition originalVisPosBeforeEndBR;
     if (endBR)
         originalVisPosBeforeEndBR = VisiblePosition(positionBeforeNode(endBR)).previous();
 
     RefPtrWillBeRawPtr<Element> enclosingBlockOfInsertionPos = enclosingBlock(insertionPos.anchorNode());
 
     // Adjust insertionPos to prevent nesting.
     // If the start was in a Mail blockquote, we will have already handled adjusting insertionPos above.
     if (m_preventNesting && enclosingBlockOfInsertionPos && !isTableCell(enclosingBlockOfInsertionPos.get()) && !startIsInsideMailBlockquote) {
         ASSERT(enclosingBlockOfInsertionPos != currentRoot);
@@ skipping 169 matching lines @@
         if (startOfParagraph(endOfInsertedContent).deepEquivalent() == startOfParagraphToMove.deepEquivalent()) {
             insertNodeAt(createBreakElement(document()).get(), endOfInsertedContent.deepEquivalent());
             // Mutation events (bug 22634) triggered by inserting the <br> might have removed the content we're about to move
             if (!startOfParagraphToMove.deepEquivalent().inDocument())
                 return;
         }
 
         // FIXME: Maintain positions for the start and end of inserted content instead of keeping nodes.  The nodes are
         // only ever used to create positions where inserted content starts/ends.
         moveParagraph(startOfParagraphToMove, endOfParagraph(startOfParagraphToMove), destination);
-        m_startOfInsertedContent = endingSelection().visibleStart().deepEquivalent().downstream();
+        m_startOfInsertedContent = mostForwardCaretPosition(endingSelection().visibleStart().deepEquivalent());
         if (m_endOfInsertedContent.isOrphan())
-            m_endOfInsertedContent = endingSelection().visibleEnd().deepEquivalent().upstream();
+            m_endOfInsertedContent = mostBackwardCaretPosition(endingSelection().visibleEnd().deepEquivalent());
     }
 
     Position lastPositionToSelect;
     if (fragment.hasInterchangeNewlineAtEnd()) {
         VisiblePosition endOfInsertedContent = positionAtEndOfInsertedContent();
         VisiblePosition next = endOfInsertedContent.next(CannotCrossEditingBoundary);
 
         if (selectionEndWasEndOfParagraph || !isEndOfParagraph(endOfInsertedContent) || next.isNull()) {
             if (!isStartOfParagraph(endOfInsertedContent)) {
                 setEndingSelection(endOfInsertedContent);
                 Element* enclosingBlockElement = enclosingBlock(endOfInsertedContent.deepEquivalent().anchorNode());
                 if (isListItem(enclosingBlockElement)) {
                     RefPtrWillBeRawPtr<HTMLLIElement> newListItem = createListItemElement(document());
                     insertNodeAfter(newListItem, enclosingBlockElement);
                     setEndingSelection(VisiblePosition(firstPositionInNode(newListItem.get())));
                 } else {
                     // Use a default paragraph element (a plain div) for the empty paragraph, using the last paragraph
                     // block's style seems to annoy users.
                     insertParagraphSeparator(true, !startIsInsideMailBlockquote && highestEnclosingNodeOfType(endOfInsertedContent.deepEquivalent(),
                         isMailHTMLBlockquoteElement, CannotCrossEditingBoundary, insertedNodes.firstNodeInserted()->parentNode()));
                 }
 
                 // Select up to the paragraph separator that was added.
                 lastPositionToSelect = endingSelection().visibleStart().deepEquivalent();
                 updateNodesInserted(lastPositionToSelect.anchorNode());
             }
         } else {
             // Select up to the beginning of the next paragraph.
-            lastPositionToSelect = next.deepEquivalent().downstream();
+            lastPositionToSelect = mostForwardCaretPosition(next.deepEquivalent());
         }
     } else {
         mergeEndIfNeeded();
     }
 
     if (HTMLQuoteElement* mailBlockquote = toHTMLQuoteElement(enclosingNodeOfType(positionAtStartOfInsertedContent().deepEquivalent(), isMailPasteAsQuotationHTMLBlockQuoteElement)))
         removeElementAttribute(mailBlockquote, classAttr);
 
     if (shouldPerformSmartReplace())
         addSpacesForSmartReplace();
@@ skipping 41 matching lines @@
 static bool isCharacterSmartReplaceExemptConsideringNonBreakingSpace(UChar32 character, bool previousCharacter)
 {
     return isCharacterSmartReplaceExempt(character == noBreakSpaceCharacter ? ' ' : character, previousCharacter);
 }
 
 void ReplaceSelectionCommand::addSpacesForSmartReplace()
 {
     VisiblePosition startOfInsertedContent = positionAtStartOfInsertedContent();
     VisiblePosition endOfInsertedContent = positionAtEndOfInsertedContent();
 
-    Position endUpstream = endOfInsertedContent.deepEquivalent().upstream();
+    Position endUpstream = mostBackwardCaretPosition(endOfInsertedContent.deepEquivalent());
     Node* endNode = endUpstream.computeNodeBeforePosition();
     int endOffset = endNode && endNode->isTextNode() ? toText(endNode)->length() : 0;
     if (endUpstream.isOffsetInAnchor()) {
         endNode = endUpstream.computeContainerNode();
         endOffset = endUpstream.offsetInContainerNode();
     }
 
     bool needsTrailingSpace = !isEndOfParagraph(endOfInsertedContent) && !isCharacterSmartReplaceExemptConsideringNonBreakingSpace(endOfInsertedContent.characterAfter(), false);
     if (needsTrailingSpace && endNode) {
         bool collapseWhiteSpace = !endNode->layoutObject() || endNode->layoutObject()->style()->collapseWhiteSpace();
         if (endNode->isTextNode()) {
             insertTextIntoNode(toText(endNode), endOffset, collapseWhiteSpace ? nonBreakingSpaceString() : " ");
             if (m_endOfInsertedContent.computeContainerNode() == endNode)
                 m_endOfInsertedContent = Position(endNode, m_endOfInsertedContent.offsetInContainerNode() + 1);
         } else {
             RefPtrWillBeRawPtr<Text> node = document().createEditingTextNode(collapseWhiteSpace ? nonBreakingSpaceString() : " ");
             insertNodeAfter(node, endNode);
             updateNodesInserted(node.get());
         }
     }
 
     document().updateLayout();
 
-    Position startDownstream = startOfInsertedContent.deepEquivalent().downstream();
+    Position startDownstream = mostForwardCaretPosition(startOfInsertedContent.deepEquivalent());
     Node* startNode = startDownstream.computeNodeAfterPosition();
     unsigned startOffset = 0;
     if (startDownstream.isOffsetInAnchor()) {
         startNode = startDownstream.computeContainerNode();
         startOffset = startDownstream.offsetInContainerNode();
     }
 
     bool needsLeadingSpace = !isStartOfParagraph(startOfInsertedContent) && !isCharacterSmartReplaceExemptConsideringNonBreakingSpace(startOfInsertedContent.previous().characterAfter(), true);
     if (needsLeadingSpace && startNode) {
         bool collapseWhiteSpace = !startNode->layoutObject() || startNode->layoutObject()->style()->collapseWhiteSpace();
@@ skipping 169 matching lines @@
         return false;
 
     // FIXME: Would be nice to handle smart replace in the fast path.
     if (m_smartReplace || fragment.hasInterchangeNewlineAtStart() || fragment.hasInterchangeNewlineAtEnd())
         return false;
 
     // e.g. when "bar" is inserted after "foo" in <div><u>foo</u></div>, "bar" should not be underlined.
     if (elementToSplitToAvoidPastingIntoInlineElementsWithStyle(endingSelection().start()))
         return false;
 
-    RefPtrWillBeRawPtr<Node> nodeAfterInsertionPos = endingSelection().end().downstream().anchorNode();
+    RefPtrWillBeRawPtr<Node> nodeAfterInsertionPos = mostForwardCaretPosition(endingSelection().end()).anchorNode();
     Text* textNode = toText(fragment.firstChild());
     // Our fragment creation code handles tabs, spaces, and newlines, so we don't have to worry about those here.
 
     Position start = endingSelection().start();
     Position end = replaceSelectedTextInNode(textNode->data());
     if (end.isNull())
         return false;
 
     if (nodeAfterInsertionPos && nodeAfterInsertionPos->parentNode() && isHTMLBRElement(*nodeAfterInsertionPos)
         && shouldRemoveEndBR(toHTMLBRElement(nodeAfterInsertionPos.get()), VisiblePosition(positionBeforeNode(nodeAfterInsertionPos.get()))))
         removeNodeAndPruneAncestors(nodeAfterInsertionPos.get());
 
     VisibleSelection selectionAfterReplace(m_selectReplacement ? start : end, end);
 
     setEndingSelection(selectionAfterReplace);
 
     return true;
 }
 
 DEFINE_TRACE(ReplaceSelectionCommand)
 {
     visitor->trace(m_startOfInsertedContent);
     visitor->trace(m_endOfInsertedContent);
     visitor->trace(m_insertionStyle);
     visitor->trace(m_documentFragment);
     CompositeEditCommand::trace(visitor);
 }
 
 } // namespace blink