Promptly finalize CacheStorage's embedder object.

Source/modules/cachestorage/CacheStorage.h

Index: Source/modules/cachestorage/CacheStorage.h
diff --git a/Source/modules/cachestorage/CacheStorage.h b/Source/modules/cachestorage/CacheStorage.h
index e7df6a7dedcbf9cd109d9e7a128d5e56b413141f..90d80328a73c60dc026fab55eae147190b0d2f84 100644
--- a/Source/modules/cachestorage/CacheStorage.h
+++ b/Source/modules/cachestorage/CacheStorage.h
@@ -26,6 +26,8 @@ class CacheStorage final : public GarbageCollectedFinalized<CacheStorage>, publi
     WTF_MAKE_NONCOPYABLE(CacheStorage);
 public:
     static CacheStorage* create(WeakPtr<GlobalFetch::ScopedFetcher>, WebServiceWorkerCacheStorage*);
+    ~CacheStorage();
+    void dispose();
 
     ScriptPromise open(ScriptState*, const String& cacheName);
     ScriptPromise has(ScriptState*, const String& cacheName);
@@ -33,7 +35,6 @@ public:
     ScriptPromise keys(ScriptState*);
     ScriptPromise match(ScriptState*, const RequestInfo&, const CacheQueryOptions&, ExceptionState&);
 
-
     DECLARE_TRACE();
 
 private: