Remove some dead code from rendering/ folder

Source/core/rendering/RenderBlockFlow.cpp

Index: Source/core/rendering/RenderBlockFlow.cpp
diff --git a/Source/core/rendering/RenderBlockFlow.cpp b/Source/core/rendering/RenderBlockFlow.cpp
index 1ac818d3edd81b70fde14c786142593f90e75efa..3527a600a8c528e10d3a7f209b1563d26cc184b3 100644
--- a/Source/core/rendering/RenderBlockFlow.cpp
+++ b/Source/core/rendering/RenderBlockFlow.cpp
@@ -170,11 +170,6 @@ RenderBlockFlow* RenderBlockFlow::createAnonymous(Document* document)
     return renderer;
 }
 
-RenderBlockFlow* RenderBlockFlow::createAnonymousBlockFlow() const
-{
-    return toRenderBlockFlow(createAnonymousWithParentRendererAndDisplay(this, BLOCK));
-}
-
 RenderObject* RenderBlockFlow::layoutSpecialExcludedChild(bool relayoutChildren, SubtreeLayoutScope& layoutScope)
 {
     RenderMultiColumnFlowThread* flowThread = multiColumnFlowThread();