IndexedDBQuotaClient doesn't need to inherit from storage::QuotaTaskObserver

content/browser/indexed_db/indexed_db_quota_client.h

 // Copyright (c) 2011 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 CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_QUOTA_CLIENT_H_
 #define CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_QUOTA_CLIENT_H_
 
 #include <set>
 #include <string>
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "base/message_loop/message_loop_proxy.h"
 #include "content/common/content_export.h"
 #include "storage/browser/quota/quota_client.h"
 #include "storage/browser/quota/quota_task.h"
 #include "storage/common/quota/quota_types.h"
 
 namespace content {
 class IndexedDBContextImpl;
 
 // A QuotaClient implementation to integrate IndexedDB
 // with the quota  management system. This interface is used
 // on the IO thread by the quota manager.
-class IndexedDBQuotaClient : public storage::QuotaClient,
-                             public storage::QuotaTaskObserver {
+class IndexedDBQuotaClient : public storage::QuotaClient {
  public:
   CONTENT_EXPORT explicit IndexedDBQuotaClient(
       IndexedDBContextImpl* indexed_db_context);
   CONTENT_EXPORT ~IndexedDBQuotaClient() override;
 
   // QuotaClient method overrides
   ID id() const override;
   void OnQuotaManagerDestroyed() override;
   CONTENT_EXPORT void GetOriginUsage(const GURL& origin_url,
                                      storage::StorageType type,
@@ skipping 13 matching lines @@
 
  private:
   scoped_refptr<IndexedDBContextImpl> indexed_db_context_;
 
   DISALLOW_COPY_AND_ASSIGN(IndexedDBQuotaClient);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_QUOTA_CLIENT_H_