IntersectionObserver: second cut.

third_party/WebKit/Source/core/dom/ElementRareData.cpp

Index: third_party/WebKit/Source/core/dom/ElementRareData.cpp
diff --git a/third_party/WebKit/Source/core/dom/ElementRareData.cpp b/third_party/WebKit/Source/core/dom/ElementRareData.cpp
index 2014dd81b79d4a47dd76e735c4e8aefa74a09646..c5c756cf0a1597dd8f40c0823aaabefac1b6e8e4 100644
--- a/third_party/WebKit/Source/core/dom/ElementRareData.cpp
+++ b/third_party/WebKit/Source/core/dom/ElementRareData.cpp
@@ -29,7 +29,6 @@
  */
 
 #include "core/dom/ElementRareData.h"
-
 #include "core/dom/CompositorProxiedPropertySet.h"
 #include "core/style/ComputedStyle.h"
 
@@ -40,7 +39,7 @@ struct SameSizeAsElementRareData : NodeRareData {
     LayoutSize sizeForResizing;
     IntSize scrollOffset;
     void* pointers[13];
-    PersistentWillBeMember<void*> member[1];
+    PersistentWillBeMember<void*> persistentMember[2];
 };
 
 CSSStyleDeclaration& ElementRareData::ensureInlineCSSStyleDeclaration(Element* ownerElement)
@@ -73,6 +72,7 @@ DEFINE_TRACE_AFTER_DISPATCH(ElementRareData)
     visitor->trace(m_generatedAfter);
     visitor->trace(m_generatedFirstLetter);
     visitor->trace(m_backdrop);
+    visitor->trace(m_intersectionObserverData);
     NodeRareData::traceAfterDispatch(visitor);
 }