Oilpan: account for V8NPObject::rootObject bare pointer.

third_party/WebKit/Source/bindings/core/v8/NPV8Object.h

Index: third_party/WebKit/Source/bindings/core/v8/NPV8Object.h
diff --git a/third_party/WebKit/Source/bindings/core/v8/NPV8Object.h b/third_party/WebKit/Source/bindings/core/v8/NPV8Object.h
index 543af66ba7493b60f11715525b1f0bac27b289f1..89f8513147ff69d0901be821166000a8f9c05f39 100644
--- a/third_party/WebKit/Source/bindings/core/v8/NPV8Object.h
+++ b/third_party/WebKit/Source/bindings/core/v8/NPV8Object.h
@@ -34,6 +34,8 @@
 #include "bindings/core/v8/V8DOMWrapper.h"
 #include "core/CoreExport.h"
 
+#include "platform/heap/Handle.h"
+
 // Chromium uses npruntime.h from the Chromium source repository under
 // third_party/npapi/bindings.
 #include <bindings/npruntime.h>
@@ -56,7 +58,7 @@ struct V8NPObject {
 public:
     NPObject object;
     v8::Persistent<v8::Object> v8Object;
-    LocalDOMWindow* rootObject;
+    RawPtrWillBeUntracedMember<LocalDOMWindow> rootObject;
 };
 
 struct PrivateIdentifier {