WIP: Introduce per-TabContents PrefService.

chrome/browser/prefs/tab_contents_user_pref_store.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 CHROME_BROWSER_PREFS_TAB_CONTENTS_USER_PREF_STORE_H_
+#define CHROME_BROWSER_PREFS_TAB_CONTENTS_USER_PREF_STORE_H_
+#pragma once
+
+// PersistentPrefStore implementation used with per-TabContents PrefService
+// instances. It's based on PrefValueMap and not persisted to disk.
+class TabContentsUserPrefStore : public PersistentPrefStore {
+ public:
+  TabContentsUserPrefStore();
+  virtual ~TabContentsUserPrefStore();
+
+  // Methods of PrefStore.
+  virtual void AddObserver(PrefStore::Observer* observer) OVERRIDE;
+  virtual void RemoveObserver(PrefStore::Observer* observer) OVERRIDE;
+  virtual bool IsInitializationComplete() const OVERRIDE;
+  virtual ReadResult GetValue(const std::string& key,
+                              const base::Value** result) const OVERRIDE;
+
+  // PersistentPrefStore implementation:
+  virtual ReadResult GetMutableValue(const std::string& key,
+                                     base::Value** result) OVERRIDE;
+  virtual void ReportValueChanged(const std::string& key) OVERRIDE;
+  virtual void SetValue(const std::string& key, base::Value* value) OVERRIDE;
+  virtual void SetValueSilently(const std::string& key,
+                                base::Value* value) OVERRIDE;
+  virtual void RemoveValue(const std::string& key) OVERRIDE;
+  virtual bool ReadOnly() const OVERRIDE;
+  virtual PrefReadError ReadPrefs() OVERRIDE;
+  virtual void ReadPrefsAsync(ReadErrorDelegate* error_delegate) OVERRIDE;
+  virtual bool WritePrefs() OVERRIDE;
+  virtual void ScheduleWritePrefs() OVERRIDE;
+  virtual void CommitPendingWrite() OVERRIDE;
+
+ private:
+  PrefValueMap pref_values_;
+
+  DISALLOW_COPY_AND_ASSIGN(TabContentsUserPrefStore);
+};
+
+#endif  // CHROME_BROWSER_PREFS_TAB_CONTENTS_USER_PREF_STORE_H_