1. Check that ClassicPendingScript is not accessed after prefinalizer explicitly

third_party/WebKit/Source/core/dom/ClassicPendingScript.h

Index: third_party/WebKit/Source/core/dom/ClassicPendingScript.h
diff --git a/third_party/WebKit/Source/core/dom/ClassicPendingScript.h b/third_party/WebKit/Source/core/dom/ClassicPendingScript.h
index 00b2e4415e22449b2b6948e21fc4e6f70d2809a1..0405f5b99bafc6797e818c2cb045d1a8da683cac 100644
--- a/third_party/WebKit/Source/core/dom/ClassicPendingScript.h
+++ b/third_party/WebKit/Source/core/dom/ClassicPendingScript.h
@@ -86,6 +86,12 @@ class CORE_EXPORT ClassicPendingScript final
   bool integrity_failure_;
 
   Member<ScriptStreamer> streamer_;
+
+  // This is a temporary flag to confirm that ClassicPendingScript is not
+  // touched after its refinalizer call and thus https://crbug.com/715309
+  // doesn't break assumptions.
+  // TODO(hiroshige): Check the state in more general way.
+  bool prefinalizer_called_ = false;
 };
 
 }  // namespace blink