Introduce LayoutObject::createPositionWithAffinity(int offset)

Source/core/layout/LayoutText.cpp

Index: Source/core/layout/LayoutText.cpp
diff --git a/Source/core/layout/LayoutText.cpp b/Source/core/layout/LayoutText.cpp
index ac36dc083ba35685a1bf8b5d22a0079e180c6ea5..ac5915b3e96bceac4fe35d8bdb4bc7a7bdba4a0e 100644
--- a/Source/core/layout/LayoutText.cpp
+++ b/Source/core/layout/LayoutText.cpp
@@ -595,7 +595,7 @@ static PositionWithAffinity createPositionWithAffinityForBoxAfterAdjustingOffset
 PositionWithAffinity LayoutText::positionForPoint(const LayoutPoint& point)
 {
     if (!firstTextBox() || textLength() == 0)
-        return createPositionWithAffinity(0, DOWNSTREAM);
+        return createPositionWithAffinity(0);
 
     LayoutUnit pointLineDirection = firstTextBox()->isHorizontal() ? point.x() : point.y();
     LayoutUnit pointBlockDirection = firstTextBox()->isHorizontal() ? point.y() : point.x();
@@ -627,7 +627,7 @@ PositionWithAffinity LayoutText::positionForPoint(const LayoutPoint& point)
         lineDirectionPointFitsInBox(pointLineDirection, lastBox, shouldAffinityBeDownstream);
         return createPositionWithAffinityForBoxAfterAdjustingOffsetForBiDi(lastBox, lastBox->offsetForPosition(pointLineDirection.toFloat()) + lastBox->start(), shouldAffinityBeDownstream);
     }
-    return createPositionWithAffinity(0, DOWNSTREAM);
+    return createPositionWithAffinity(0);
 }
 
 LayoutRect LayoutText::localCaretRect(InlineBox* inlineBox, int caretOffset, LayoutUnit* extraWidthToEndOfLine)