Introduce createMarkup function takes two positions

Source/core/editing/markup.cpp

Index: Source/core/editing/markup.cpp
diff --git a/Source/core/editing/markup.cpp b/Source/core/editing/markup.cpp
index 505ecad6725a34c1cf7738181d4dbce1b3888e99..9ef7d6b635a91d1502fe5be4377f510decbd9aad 100644
--- a/Source/core/editing/markup.cpp
+++ b/Source/core/editing/markup.cpp
@@ -184,9 +184,10 @@ template<typename PositionType>
 static bool areSameRanges(Node* node, const PositionType& startPosition, const PositionType& endPosition)
 {
     ASSERT(node);
-    Position otherStartPosition;
-    Position otherEndPosition;
-    VisibleSelection::selectionFromContentsOfNode(node).toNormalizedPositions(otherStartPosition, otherEndPosition);
+
+    PositionType otherStartPosition;
+    PositionType otherEndPosition;
+    VisibleSelection::normalizePositions(PositionType::firstPositionInNode(node), PositionType::lastPositionInNode(node), &otherStartPosition, &otherEndPosition);
     return startPosition == otherStartPosition && endPosition == otherEndPosition;
 }
 
@@ -239,6 +240,14 @@ static HTMLElement* highestAncestorToWrapMarkup(const typename Strategy::Positio
     return specialCommonAncestor;
 }
 
+template <typename Strategy>
+class CreateMarkupAlgorithm {
+public:
+    using PositionType = typename Strategy::PositionType;
+
+    static String createMarkup(const PositionType& startPosition, const PositionType& endPosition, EAnnotateForInterchange shouldAnnotate = DoNotAnnotateForInterchange, ConvertBlocksToInlines = ConvertBlocksToInlines::NotConvert, EAbsoluteURLs shouldResolveURLs = DoNotResolveURLs, Node* constrainingAncestor = nullptr);
+};
+
 // FIXME: Shouldn't we omit style info when annotate == DoNotAnnotateForInterchange?
 // FIXME: At least, annotation and style info should probably not be included in range.markupString()
 template <typename Strategy>
@@ -272,6 +281,12 @@ String createMarkup(const Range* range, EAnnotateForInterchange shouldAnnotate,
     return CreateMarkupAlgorithm<EditingStrategy>::createMarkup(range->startPosition(), range->endPosition(), shouldAnnotate, convertBlocksToInlines, shouldResolveURLs, constrainingAncestor);
 }
 
+String createMarkup(const Position& startPosition, const Position& endPosition, EAnnotateForInterchange shouldAnnotate, ConvertBlocksToInlines convertBlocksToInlines, EAbsoluteURLs shouldResolveURLs, Node* constrainingAncestor)
+{
+    ASSERT(startPosition.compareTo(endPosition) <= 0);
+    return CreateMarkupAlgorithm<EditingStrategy>::createMarkup(startPosition, endPosition, shouldAnnotate, convertBlocksToInlines, shouldResolveURLs, constrainingAncestor);
+}
+
 PassRefPtrWillBeRawPtr<DocumentFragment> createFragmentFromMarkup(Document& document, const String& markup, const String& baseURL, ParserContentPolicy parserContentPolicy)
 {
     // We use a fake body element here to trick the HTML parser to using the InBody insertion mode.