Change SelectionStartEnd() returning values instead of assigning into ref args.

third_party/WebKit/Source/core/layout/LayoutObject.cpp

Index: third_party/WebKit/Source/core/layout/LayoutObject.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutObject.cpp b/third_party/WebKit/Source/core/layout/LayoutObject.cpp
index 57050627de17fafbb5179957e1627db37958916b..eb18e100ebbb8858b567e9d45ff375d33fa6f6d0 100644
--- a/third_party/WebKit/Source/core/layout/LayoutObject.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutObject.cpp
@@ -1453,9 +1453,9 @@ Color LayoutObject::SelectionEmphasisMarkColor(
   return SelectionColor(CSSPropertyWebkitTextEmphasisColor, global_paint_flags);
 }
 
-void LayoutObject::SelectionStartEnd(int& start_pos, int& end_pos) const {
+std::pair<int, int> LayoutObject::SelectionStartEnd() const {
   DCHECK(!View()->NeedsLayout());
-  GetFrame()->Selection().LayoutSelectionStartEnd(start_pos, end_pos);
+  return GetFrame()->Selection().LayoutSelectionStartEnd();
 }
 
 // Called when an object that was floating or positioned becomes a normal flow