Introduce DEFINE_RENDER_OBJECT_TYPE_CASTS to replace manual toRenderFoo, and use it

Source/core/rendering/RenderFlowThread.h

 /*
  * Copyright (C) 2011 Adobe Systems Incorporated. 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.
@@ skipping 273 matching lines @@
     bool m_dispatchRegionOversetChangeEvent : 1;
     bool m_pageLogicalSizeChanged : 1;
     bool m_inConstrainedLayoutPhase : 1;
     bool m_needsTwoPhasesLayout : 1;
 
 private:
     virtual bool supportsPartialLayout() const OVERRIDE { return false; }
 
 };
 
-inline RenderFlowThread* toRenderFlowThread(RenderObject* object)
-{
-    ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isRenderFlowThread());
-    return static_cast<RenderFlowThread*>(object);
-}
-
-inline const RenderFlowThread* toRenderFlowThread(const RenderObject* object)
-{
-    ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isRenderFlowThread());
-    return static_cast<const RenderFlowThread*>(object);
-}
-
-// This will catch anyone doing an unnecessary cast.
-void toRenderFlowThread(const RenderFlowThread*);
+DEFINE_RENDER_OBJECT_TYPE_CASTS(RenderFlowThread, isRenderFlowThread());
 
 class CurrentRenderFlowThreadMaintainer {
     WTF_MAKE_NONCOPYABLE(CurrentRenderFlowThreadMaintainer);
 public:
     CurrentRenderFlowThreadMaintainer(RenderFlowThread*);
     ~CurrentRenderFlowThreadMaintainer();
 private:
     RenderFlowThread* m_renderFlowThread;
     RenderFlowThread* m_previousRenderFlowThread;
 };
 
 // These structures are used by PODIntervalTree for debugging.
 #ifndef NDEBUG
 template <> struct ValueToString<LayoutUnit> {
     static String string(const LayoutUnit value) { return String::number(value.toFloat()); }
 };
 
 template <> struct ValueToString<RenderRegion*> {
     static String string(const RenderRegion* value) { return String::format("%p", value); }
 };
 #endif
 
 } // namespace WebCore
 
 #endif // RenderFlowThread_h