Revert of Move ThreadableLoader to Oilpan heap (2/3)

third_party/WebKit/Source/modules/notifications/NotificationImageLoader.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef NotificationImageLoader_h
 #define NotificationImageLoader_h
 
 #include "core/loader/ThreadableLoader.h"
 #include "core/loader/ThreadableLoaderClient.h"
 #include "platform/SharedBuffer.h"
@@ skipping 28 matching lines @@
     // Cancels the pending load, if there is one. The |m_imageCallback| will not
     // be run.
     void stop();
 
     // ThreadableLoaderClient interface.
     void didReceiveData(const char* data, unsigned length) override;
     void didFinishLoading(unsigned long resourceIdentifier, double finishTime) override;
     void didFail(const ResourceError&) override;
     void didFailRedirectCheck() override;
 
-    DEFINE_INLINE_TRACE()
-    {
-        visitor->trace(m_threadableLoader);
-    }
+    DEFINE_INLINE_TRACE() {}
 
 private:
     void runCallbackWithEmptyBitmap();
 
     bool m_stopped;
     double m_startTime;
     RefPtr<SharedBuffer> m_data;
     std::unique_ptr<ImageCallback> m_imageCallback;
-    Member<ThreadableLoader> m_threadableLoader;
+    std::unique_ptr<ThreadableLoader> m_threadableLoader;
 };
 
 } // namespace blink
 
 #endif // NotificationImageLoader_h