Get rid of a redundant argument DOWNSTREAM from PositionWithAffinity constructor call sites

Source/core/layout/LayoutObject.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  *           (C) 2004 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Google Inc. All rights reserved.
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 2995 matching lines @@
     // regions of the document, but that is either impossible or at least
     // extremely unlikely in any normal case because we stop as soon as we
     // find a single non-anonymous layoutObject.
 
     // Find a nearby non-anonymous layoutObject.
     LayoutObject* child = this;
     while (LayoutObject* parent = child->parent()) {
         // Find non-anonymous content after.
         for (LayoutObject* layoutObject = child->nextInPreOrder(parent); layoutObject; layoutObject = layoutObject->nextInPreOrder(parent)) {
             if (Node* node = layoutObject->nonPseudoNode())
-                return PositionWithAffinity(firstPositionInOrBeforeNode(node), DOWNSTREAM);
+                return PositionWithAffinity(firstPositionInOrBeforeNode(node));
         }
 
         // Find non-anonymous content before.
         for (LayoutObject* layoutObject = child->previousInPreOrder(); layoutObject; layoutObject = layoutObject->previousInPreOrder()) {
             if (layoutObject == parent)
                 break;
             if (Node* node = layoutObject->nonPseudoNode())
-                return PositionWithAffinity(lastPositionInOrAfterNode(node), DOWNSTREAM);
+                return PositionWithAffinity(lastPositionInOrAfterNode(node));
         }
 
         // Use the parent itself unless it too is anonymous.
         if (Node* node = parent->nonPseudoNode())
-            return PositionWithAffinity(firstPositionInOrBeforeNode(node), DOWNSTREAM);
+            return PositionWithAffinity(firstPositionInOrBeforeNode(node));
 
         // Repeat at the next level up.
         child = parent;
     }
 
     // Everything was anonymous. Give up.
     return PositionWithAffinity();
 }
 
 PositionWithAffinity LayoutObject::createPositionWithAffinity(const Position& position)
@@ skipping 357 matching lines @@
         const blink::LayoutObject* root = object1;
         while (root->parent())
             root = root->parent();
         root->showLayoutTreeAndMark(object1, "*", object2, "-", 0);
     } else {
         fprintf(stderr, "Cannot showLayoutTree. Root is (nil)\n");
     }
 }
 
 #endif