Remove unused RenderBlock::regionAtBlockOffset()

Source/core/rendering/RenderBlock.cpp

Index: Source/core/rendering/RenderBlock.cpp
diff --git a/Source/core/rendering/RenderBlock.cpp b/Source/core/rendering/RenderBlock.cpp
index 3493f57328b02b3a860375b41de0813bc6c2f7d8..b1372a6f03780f92ea49341d10428efe3db84b44 100644
--- a/Source/core/rendering/RenderBlock.cpp
+++ b/Source/core/rendering/RenderBlock.cpp
@@ -4850,15 +4850,6 @@ LayoutUnit RenderBlock::offsetFromLogicalTopOfFirstPage() const
     return 0;
 }
 
-RenderRegion* RenderBlock::regionAtBlockOffset(LayoutUnit blockOffset) const
-{
-    RenderFlowThread* flowThread = flowThreadContainingBlock();
-    if (!flowThread || !flowThread->hasValidRegionInfo())
-        return 0;
-
-    return flowThread->regionAtBlockOffset(offsetFromLogicalTopOfFirstPage() + blockOffset, true);
-}
-
 LayoutUnit RenderBlock::collapsedMarginBeforeForChild(const RenderBox* child) const
 {
     // If the child has the same directionality as we do, then we can just return its