Remove the migration code from content_settings::DefaultProvider.

components/content_settings/core/browser/content_settings_default_provider.h

Index: components/content_settings/core/browser/content_settings_default_provider.h
diff --git a/components/content_settings/core/browser/content_settings_default_provider.h b/components/content_settings/core/browser/content_settings_default_provider.h
index 86ec1c847d217ddc96bcea5cb7aeee003b7bf79b..52b668c179149a22bb4565a2d79ca52ec12f5893 100644
--- a/components/content_settings/core/browser/content_settings_default_provider.h
+++ b/components/content_settings/core/browser/content_settings_default_provider.h
@@ -53,7 +53,7 @@ class DefaultProvider : public ObservableProvider {
   typedef linked_ptr<base::Value> ValuePtr;
   typedef std::map<ContentSettingsType, ValuePtr> ValueMap;
 
-  // Reads all individual settings from the pref service.
+  // Reads all settings from the pref service.
   void ReadDefaultSettings();
 
   // Change the remembered setting in the memory.
@@ -63,43 +63,23 @@ class DefaultProvider : public ObservableProvider {
   bool IsValueEmptyOrDefault(ContentSettingsType content_type,
                              base::Value* value);
 
-  // Parses a |DictionaryValue| into a |ValueMap|.
-  scoped_ptr<ValueMap> GetSettingsFromDictionary(
-      const base::DictionaryValue* dictionary);
-
   // Forces the default settings in |value_map| to be explicitly set instead
   // of themselves being CONTENT_SETTING_DEFAULT.
   void ForceDefaultsToBeExplicit(ValueMap* value_map);
 
-  // Reads the dictionary prefrence and returns the dictionary parsed as
-  // a |ValueMap|.
-  scoped_ptr<ValueMap> ReadDictionaryPref();
-
-  // Reads an individual preference.
-  scoped_ptr<base::Value> ReadIndividualPref(ContentSettingsType content_type);
+  // Reads the preference corresponding to |content_type|.
+  scoped_ptr<base::Value> ReadFromPref(ContentSettingsType content_type);
 
-  // Writes the value |value| to the individual preference corresponding
-  // to |content_type|. It's the responsibility of caller to obtain a lock
-  // and notify observers.
-  void WriteIndividualPref(ContentSettingsType content_type,
-                           base::Value* value);
-
-  // Writes the value |value| to the dictionary preference entry corresponding
-  // to |content_type|. It's the responsibility of caller to obtain a lock
-  // and notify observers.
-  void WriteDictionaryPref(ContentSettingsType content_type,
-                           base::Value* value);
+  // Writes the value |value| to the preference corresponding to |content_type|.
+  // It's the responsibility of caller to obtain a lock and notify observers.
+  void WriteToPref(ContentSettingsType content_type,
+                   base::Value* value);
 
   // Called on prefs change.
   void OnPreferenceChanged(const std::string& pref_name);
 
-  // Migrates the dictionary settings to the individual settings. Only called
-  // once during the first run.
-  void MigrateDefaultSettings();
-
-  // Migrates the obsolete media stream default setting to the new microphone
-  // and camera settings.
-  void MigrateObsoleteMediaContentSetting();
+  // Clean up the obsolete preferences from the user's profile.
+  void DiscardObsoletePreferences();
 
   // Copies of the pref data, so that we can read it on the IO thread.
   ValueMap default_settings_;