Pass scroll bar placement as an enum instead of std::string

Source/core/layout/LayoutScrollbar.cpp

 /*
  * Copyright (C) 2008, 2009 Apple 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 219 matching lines @@
 
     RefPtr<ComputedStyle> partStyle = !destroy ? getScrollbarPseudoStyle(partType,  pseudoForScrollbarPart(partType)) : PassRefPtr<ComputedStyle>(nullptr);
 
     bool needLayoutObject = !destroy && partStyle && partStyle->display() != NONE;
 
     if (needLayoutObject && partStyle->display() != BLOCK) {
         // See if we are a button that should not be visible according to OS settings.
         ScrollbarButtonsPlacement buttonsPlacement = theme()->buttonsPlacement();
         switch (partType) {
         case BackButtonStartPart:
-            needLayoutObject = (buttonsPlacement == ScrollbarButtonsSingle || buttonsPlacement == ScrollbarButtonsDoubleStart
-                || buttonsPlacement == ScrollbarButtonsDoubleBoth);
+            needLayoutObject = (buttonsPlacement == ScrollbarButtonsPlacementSingle || buttonsPlacement == ScrollbarButtonsPlacementDoubleStart
+                || buttonsPlacement == ScrollbarButtonsPlacementDoubleBoth);
             break;
         case ForwardButtonStartPart:
-            needLayoutObject = (buttonsPlacement == ScrollbarButtonsDoubleStart || buttonsPlacement == ScrollbarButtonsDoubleBoth);
+            needLayoutObject = (buttonsPlacement == ScrollbarButtonsPlacementDoubleStart || buttonsPlacement == ScrollbarButtonsPlacementDoubleBoth);
             break;
         case BackButtonEndPart:
-            needLayoutObject = (buttonsPlacement == ScrollbarButtonsDoubleEnd || buttonsPlacement == ScrollbarButtonsDoubleBoth);
+            needLayoutObject = (buttonsPlacement == ScrollbarButtonsPlacementDoubleEnd || buttonsPlacement == ScrollbarButtonsPlacementDoubleBoth);
             break;
         case ForwardButtonEndPart:
-            needLayoutObject = (buttonsPlacement == ScrollbarButtonsSingle || buttonsPlacement == ScrollbarButtonsDoubleEnd
-                || buttonsPlacement == ScrollbarButtonsDoubleBoth);
+            needLayoutObject = (buttonsPlacement == ScrollbarButtonsPlacementSingle || buttonsPlacement == ScrollbarButtonsPlacementDoubleEnd
+                || buttonsPlacement == ScrollbarButtonsPlacementDoubleBoth);
             break;
         default:
             break;
         }
     }
 
     LayoutScrollbarPart* partLayoutObject = m_parts.get(partType);
     if (!partLayoutObject && needLayoutObject) {
         partLayoutObject = LayoutScrollbarPart::createAnonymous(&owningLayoutObject()->document(), this, partType);
         m_parts.set(partType, partLayoutObject);
@@ skipping 100 matching lines @@
         return;
 
     // FIXME: invalidate only the changed part.
     if (LayoutBox* owningLayoutObject = this->owningLayoutObject()) {
         for (auto& part : m_parts)
             owningLayoutObject->invalidateDisplayItemClientForNonCompositingDescendantsOf(*part.value);
     }
 }
 
 }