[wrapper-tracing] MutationObserver: Add write barriers

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

Index: third_party/WebKit/Source/core/dom/Node.cpp
diff --git a/third_party/WebKit/Source/core/dom/Node.cpp b/third_party/WebKit/Source/core/dom/Node.cpp
index 84e58b59e21a593fd48aacfba45814117a409361..b6bf406adb3685974276aad6c3a2847d9b969f89 100644
--- a/third_party/WebKit/Source/core/dom/Node.cpp
+++ b/third_party/WebKit/Source/core/dom/Node.cpp
@@ -29,6 +29,7 @@
 #include "bindings/core/v8/DOMDataStore.h"
 #include "bindings/core/v8/ExceptionState.h"
 #include "bindings/core/v8/Microtask.h"
+#include "bindings/core/v8/ScriptWrappableVisitor.h"
 #include "bindings/core/v8/V8DOMWrapper.h"
 #include "core/HTMLNames.h"
 #include "core/MathMLNames.h"
@@ -294,8 +295,8 @@ NodeRareData& Node::ensureRareData() {
     m_data.m_rareData = NodeRareData::create(m_data.m_layoutObject);
 
   DCHECK(m_data.m_rareData);
-
   setFlag(HasRareDataFlag);
+  ScriptWrappableVisitor::writeBarrier(this, rareData());
   return *rareData();
 }
 
@@ -1973,6 +1974,7 @@ void Node::registerMutationObserver(
     registry.append(MutationObserverRegistration::create(
         observer, this, options, attributeFilter));
     registration = registry.last().get();
+    ScriptWrappableVisitor::writeBarrier(this, registration);
   }
 
   document().addMutationObserverTypes(registration->mutationTypes());