Revert of Remove ineffective PendingScript prefinalizer (2nd attempt.)

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

Index: third_party/WebKit/Source/core/dom/PendingScript.h
diff --git a/third_party/WebKit/Source/core/dom/PendingScript.h b/third_party/WebKit/Source/core/dom/PendingScript.h
index 89daa1578b86323f2b5496ba0b87bdc41fff7a36..97e9b384b16140bf1bc67012b37f4b9105c432b5 100644
--- a/third_party/WebKit/Source/core/dom/PendingScript.h
+++ b/third_party/WebKit/Source/core/dom/PendingScript.h
@@ -47,6 +47,7 @@
 // lifetime in order to guarantee that the data buffer will not be purged.
 class CORE_EXPORT PendingScript final : public GarbageCollectedFinalized<PendingScript>, public ResourceOwner<ScriptResource> {
     USING_GARBAGE_COLLECTED_MIXIN(PendingScript);
+    USING_PRE_FINALIZER(PendingScript, dispose);
     WTF_MAKE_NONCOPYABLE(PendingScript);
 public:
     static PendingScript* create(Element*, ScriptResource*);