Promptly finalize CacheStorage's embedder object.

Source/modules/cachestorage/GlobalCacheStorage.cpp

Index: Source/modules/cachestorage/GlobalCacheStorage.cpp
diff --git a/Source/modules/cachestorage/GlobalCacheStorage.cpp b/Source/modules/cachestorage/GlobalCacheStorage.cpp
index 00f04e397233ab88f91da4ed6a85e2fed2be3485..b436b9a78c3cf40068d0d197fb4d6b89f4b7f32a 100644
--- a/Source/modules/cachestorage/GlobalCacheStorage.cpp
+++ b/Source/modules/cachestorage/GlobalCacheStorage.cpp
@@ -33,6 +33,12 @@ public:
         return *supplement;
     }
 
+    ~GlobalCacheStorageImpl()
+    {
+        if (m_caches)
+            m_caches->dispose();
+    }
+
     CacheStorage* caches(T& fetchingScope, ExceptionState& exceptionState)
     {
         ExecutionContext* context = fetchingScope.executionContext();
@@ -54,6 +60,8 @@ public:
         return m_caches;
     }
 
+    // Promptly dispose of associated CacheStorage.
+    EAGERLY_FINALIZE();
     DEFINE_INLINE_VIRTUAL_TRACE()
     {
         visitor->trace(m_caches);