Split content settings pref related logic into a separate class

components/content_settings/core/browser/content_settings_pref.h

-// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// 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 COMPONENTS_CONTENT_SETTINGS_CORE_BROWSER_CONTENT_SETTINGS_PREF_PROVIDER_H_
-#define COMPONENTS_CONTENT_SETTINGS_CORE_BROWSER_CONTENT_SETTINGS_PREF_PROVIDER_H_
+#ifndef COMPONENTS_CONTENT_SETTINGS_CORE_BROWSER_CONTENT_SETTINGS_PREF_H_
+#define COMPONENTS_CONTENT_SETTINGS_CORE_BROWSER_CONTENT_SETTINGS_PREF_H_
 
-// A content settings provider that takes its settings out of the pref service.
+#include <string>
 
-#include <vector>
-
-#include "base/basictypes.h"
-#include "base/prefs/pref_change_registrar.h"
+#include "base/callback.h"
 #include "base/synchronization/lock.h"
-#include "components/content_settings/core/browser/content_settings_observable_provider.h"
+#include "base/threading/thread_checker.h"
+#include "base/values.h"
 #include "components/content_settings/core/browser/content_settings_origin_identifier_value_map.h"
-#include "components/content_settings/core/browser/content_settings_utils.h"
+#include "components/content_settings/core/browser/content_settings_provider.h"
+#include "components/content_settings/core/common/content_settings_pattern.h"
+#include "components/content_settings/core/common/content_settings_types.h"
 
 class PrefService;
+class PrefChangeRegistrar;
 
 namespace base {
 class Clock;
 class DictionaryValue;
 }
 
 namespace user_prefs {
 class PrefRegistrySyncable;
 }
 
 namespace content_settings {
 
-// Content settings provider that provides content settings from the user
-// preference.
-class PrefProvider : public ObservableProvider {
+class RuleIterator;
+
+// Represents a single pref for reading/writing content settings.
+// TODO(raymes): Currently all content settings types are stored in a single
+// instance of one of these. But the intention is that there will be one
+// instance of this class per content settings type.
+class ContentSettingsPref {
  public:
-  static void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry);
+  typedef base::Callback<void(const ContentSettingsPattern&,
+                              const ContentSettingsPattern&,
+                              ContentSettingsType,
+                              const std::string&)> NotifyObserversCallback;
 
-  PrefProvider(PrefService* prefs, bool incognito);
-  ~PrefProvider() override;
+  ContentSettingsPref(PrefService* prefs,
+                      PrefChangeRegistrar* registrar,
+                      base::Clock* clock,
+                      bool incognito,
+                      NotifyObserversCallback notify_callback);
+  ~ContentSettingsPref();
 
-  // ProviderInterface implementations.
   RuleIterator* GetRuleIterator(ContentSettingsType content_type,
                                 const ResourceIdentifier& resource_identifier,
-                                bool incognito) const override;
+                                bool incognito) const;
 
   bool SetWebsiteSetting(const ContentSettingsPattern& primary_pattern,
                          const ContentSettingsPattern& secondary_pattern,
                          ContentSettingsType content_type,
                          const ResourceIdentifier& resource_identifier,
-                         base::Value* value) override;
+                         base::Value* value);
 
-  void ClearAllContentSettingsRules(ContentSettingsType content_type) override;
+  void ClearAllContentSettingsRules(ContentSettingsType content_type);
 
-  void ShutdownOnUIThread() override;
-
-  // Records the last time the given pattern has used a certain content setting.
   void UpdateLastUsage(const ContentSettingsPattern& primary_pattern,
                        const ContentSettingsPattern& secondary_pattern,
                        ContentSettingsType content_type);
 
   base::Time GetLastUsage(const ContentSettingsPattern& primary_pattern,
                           const ContentSettingsPattern& secondary_pattern,
                           ContentSettingsType content_type);
 
-  // Gains ownership of |clock|.
-  void SetClockForTesting(scoped_ptr<base::Clock> clock);
+  size_t GetNumExceptions();
 
+  void SetClockForTesting(base::Clock* clock);
  private:
-  friend class DeadlockCheckerThread;  // For testing.
   // Reads all content settings exceptions from the preference and load them
   // into the |value_map_|. The |value_map_| is cleared first.
   void ReadContentSettingsFromPref();
 
   // Callback for changes in the pref with the same name.
   void OnContentSettingsPatternPairsChanged();
 
   // Update the preference that stores content settings exceptions and syncs the
   // value to the obsolete preference. When calling this function, |lock_|
   // should not be held, since this function will send out notifications of
   // preference changes.
   void UpdatePref(
       const ContentSettingsPattern& primary_pattern,
       const ContentSettingsPattern& secondary_pattern,
       ContentSettingsType content_type,
       const ResourceIdentifier& resource_identifier,
       const base::Value* value);
 
-  // Migrate the old media setting into new mic/camera content settings.
-  void MigrateObsoleteMediaContentSetting();
-
   static void CanonicalizeContentSettingsExceptions(
       base::DictionaryValue* all_settings_dictionary);
 
   // In the debug mode, asserts that |lock_| is not held by this thread. It's
   // ok if some other thread holds |lock_|, as long as it will eventually
   // release it.
   void AssertLockNotHeld() const;
 
   // Weak; owned by the Profile and reset in ShutdownOnUIThread.
   PrefService* prefs_;
 
-  // Can be set for testing.
-  scoped_ptr<base::Clock> clock_;
+  // Owned by the PrefProvider.
+  base::Clock* clock_;
+
+  // Owned by the PrefProvider.
+  PrefChangeRegistrar* registrar_;
 
   bool is_incognito_;
 
-  PrefChangeRegistrar pref_change_registrar_;
-
   // Whether we are currently updating preferences, this is used to ignore
   // notifications from the preferences service that we triggered ourself.
   bool updating_preferences_;
 
   OriginIdentifierValueMap value_map_;
 
   OriginIdentifierValueMap incognito_value_map_;
 
+  NotifyObserversCallback notify_callback_;
+
   // Used around accesses to the value map objects to guarantee thread safety.
   mutable base::Lock lock_;
 
-  DISALLOW_COPY_AND_ASSIGN(PrefProvider);
+  base::ThreadChecker thread_checker_;
+
+  DISALLOW_COPY_AND_ASSIGN(ContentSettingsPref);
 };
 
 }  // namespace content_settings
 
-#endif  // COMPONENTS_CONTENT_SETTINGS_CORE_BROWSER_CONTENT_SETTINGS_PREF_PROVIDER_H_
+#endif  // COMPONENTS_CONTENT_SETTINGS_CORE_BROWSER_CONTENT_SETTINGS_PREF_H_