Introduce DEFINE_RENDER_OBJECT_TYPE_CASTS to replace manual toRenderFoo, and use it

Source/core/rendering/RenderFlexibleBox.h

 /*
  * Copyright (C) 2011 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 143 matching lines @@
     void alignFlexLines(Vector<LineContext>&);
     void alignChildren(const Vector<LineContext>&);
     void applyStretchAlignmentToChild(RenderBox*, LayoutUnit lineCrossAxisExtent);
     void flipForRightToLeftColumn();
     void flipForWrapReverse(const Vector<LineContext>&, LayoutUnit crossAxisStartEdge);
 
     mutable OrderIterator m_orderIterator;
     int m_numberOfInFlowChildrenOnFirstLine;
 };
 
-inline RenderFlexibleBox* toRenderFlexibleBox(RenderObject* object)
-{
-    ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isFlexibleBox());
-    return static_cast<RenderFlexibleBox*>(object);
-}
-
-inline const RenderFlexibleBox* toRenderFlexibleBox(const RenderObject* object)
-{
-    ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isFlexibleBox());
-    return static_cast<const RenderFlexibleBox*>(object);
-}
-
-// This will catch anyone doing an unnecessary cast.
-void toRenderFlexibleBox(const RenderFlexibleBox*);
+DEFINE_RENDER_OBJECT_TYPE_CASTS(RenderFlexibleBox, isFlexibleBox());
 
 } // namespace WebCore
 
 #endif // RenderFlexibleBox_h