Abstract pref storage from net::SdchOwner

ios/crnet/sdch_owner_pref_storage.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 IOS_CRNET_SDCH_OWNER_PREF_STORAGE_H_
+#define IOS_CRNET_SDCH_OWNER_PREF_STORAGE_H_
+
+#include "base/macros.h"
+#include "base/prefs/pref_store.h"
+#include "net/sdch/sdch_owner.h"
+
+class PersistentPrefStore;
+
+// Provides an implementation of SdchOwner::PrefStorage that maps to
+// Chrome's preferences system.
+class SdchOwnerPrefStorage
+    : public net::SdchOwner::PrefStorage,
+      public PrefStore::Observer {
+ public:
+  // The storage must outlive this class.
+  explicit SdchOwnerPrefStorage(PersistentPrefStore* storage);
+  ~SdchOwnerPrefStorage() override;
+
+  ReadError GetReadError() const override;
+  bool GetValue(const base::DictionaryValue** result) const override;
+  bool GetMutableValue(base::DictionaryValue** result) override;
+  void SetValue(scoped_ptr<base::DictionaryValue> value) override;
+  void ReportValueChanged() override;
+  bool IsInitializationComplete() override;
+  void StartObservingInit(net::SdchOwner* observer) override;
+  void StopObservingInit() override;
+
+ private:
+  // PrefStore::Observer implementation.
+  void OnPrefValueChanged(const std::string& key) override;
+  void OnInitializationCompleted(bool succeeded) override;
+
+  PersistentPrefStore* storage_;  // Non-owning.
+  const std::string storage_key_;
+
+  net::SdchOwner* init_observer_;  // Non-owning.
+
+  DISALLOW_COPY_AND_ASSIGN(SdchOwnerPrefStorage);
+};
+
+#endif  // IOS_CRNET_SDCH_OWNER_PREF_STORAGE_H_