Componentization: fix SupplementTracing<0>::~SupplementTracing<0>(void) already defined.

Source/modules/storage/StorageNamespaceController.h

 // Copyright 2015 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 StorageNamespaceController_h
 #define StorageNamespaceController_h
 
 #include "core/page/Page.h"
+#include "core/page/PageSupplementable.h"
 #include "platform/Supplementable.h"
 #include "wtf/PassOwnPtr.h"
 
 namespace blink {
 
 class InspectorDOMStorageAgent;
+class Page;
 class StorageClient;
 class StorageNamespace;
 
 class StorageNamespaceController final : public NoBaseWillBeGarbageCollectedFinalized<StorageNamespaceController>, public WillBeHeapSupplement<Page> {
     WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(StorageNamespaceController);
 public:
     StorageNamespace* sessionStorage(bool optionalCreate = true);
     StorageClient* storageClient() { return m_client; }
     ~StorageNamespaceController();
 
     static void provideStorageNamespaceTo(Page&, StorageClient*);
     static StorageNamespaceController* from(Page* page) { return static_cast<StorageNamespaceController*>(WillBeHeapSupplement<Page>::from(page, supplementName())); }
 
     DECLARE_TRACE();
 
     InspectorDOMStorageAgent* inspectorAgent() { return m_inspectorAgent; }
     void setInspectorAgent(InspectorDOMStorageAgent* agent) { m_inspectorAgent = agent; }
 private:
     explicit StorageNamespaceController(StorageClient*);
     static const char* supplementName();
     OwnPtr<StorageNamespace> m_sessionStorage;
     StorageClient* m_client;
     RawPtrWillBeMember<InspectorDOMStorageAgent> m_inspectorAgent;
 };
 
 } // namespace blink
 
 #endif // StorageNamespaceController_h