Statistics of LayoutBox rare data reasons

third_party/WebKit/Source/core/layout/LayoutBlock.cpp

Index: third_party/WebKit/Source/core/layout/LayoutBlock.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutBlock.cpp b/third_party/WebKit/Source/core/layout/LayoutBlock.cpp
index 2a970993c83368ec5dcfb32438c3eac7fea2f8c5..ae153d2bdcf935728c759f82f369cd39e7234e64 100644
--- a/third_party/WebKit/Source/core/layout/LayoutBlock.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutBlock.cpp
@@ -103,6 +103,7 @@ LayoutBlock::LayoutBlock(ContainerNode* node)
       m_paginationStateChanged(false) {
   // LayoutBlockFlow calls setChildrenInline(true).
   // By default, subclasses do not have inline children.
+  m_rareStat.addReason(ReasonLBLAll);
 }
 
 void LayoutBlock::removeFromGlobalMaps() {
@@ -955,6 +956,9 @@ void LayoutBlock::insertPositionedObject(LayoutBox* o) {
   }
   descendantSet->insert(o);
 
+  o->m_rareStat.addReason(ReasonLBPositionedContainer);
+  m_rareStat.addReason(ReasonLBLPositionedDescendants);
+
   m_hasPositionedObjects = true;
 }
 
@@ -1064,6 +1068,8 @@ void LayoutBlock::addPercentHeightDescendant(LayoutBox* descendant) {
   }
   descendantSet->insert(descendant);
 
+  m_rareStat.addReason(ReasonLBLPercentHeightDescendants);
+
   m_hasPercentHeightDescendants = true;
 }