Allow whitelisted prefs to be displayed in ChromeOS in chrome://local-state.

components/prefs/pref_service.h

 // Copyright (c) 2012 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.
 
 // This provides a way to access the application's current preferences.
 
 // Chromium settings and storage represent user-selected preferences and
 // information and MUST not be extracted, overwritten or modified except
 // through Chromium defined APIs.
 
@@ skipping 239 matching lines @@
   // this checks if a value exists for the path.
   bool HasPrefPath(const std::string& path) const;
 
   // Returns a dictionary with effective preference values.
   scoped_ptr<base::DictionaryValue> GetPreferenceValues() const;
 
   // Returns a dictionary with effective preference values, omitting prefs that
   // are at their default values.
   scoped_ptr<base::DictionaryValue> GetPreferenceValuesOmitDefaults() const;
 
+  // Same as GetPreferenceValuesOmitDefaults, but also filters out preferences
+  // keys that do not match one of the prefixes in |whitelisted_prefixes|.
+  scoped_ptr<base::DictionaryValue> GetWhitelistedPreferenceValuesOmitDefaults(
+      const std::vector<std::string>& whitelisted_prefixes) const;
+
   // Returns a dictionary with effective preference values. Contrary to
   // GetPreferenceValues(), the paths of registered preferences are not split on
   // '.' characters. If a registered preference stores a dictionary, however,
   // the hierarchical structure inside the preference will be preserved.
   // For example, if "foo.bar" is a registered preference, the result could look
   // like this:
   //   {"foo.bar": {"a": {"b": true}}}.
   scoped_ptr<base::DictionaryValue> GetPreferenceValuesWithoutPathExpansion()
       const;
 
@@ skipping 71 matching lines @@
   //
   // If the pref at the given path changes, we call the observer's
   // OnPreferenceChanged method. Note that observers should not call
   // these methods directly but rather use a PrefChangeRegistrar to
   // make sure the observer gets cleaned up properly.
   //
   // Virtual for testing.
   virtual void AddPrefObserver(const std::string& path, PrefObserver* obs);
   virtual void RemovePrefObserver(const std::string& path, PrefObserver* obs);
 
+  // Helper function that adds a preference value to a dictionary if it is not
+  // at its default value.
+  void SetPreferenceOmitdefault(const std::string& pref_name,
+                                base::DictionaryValue* out) const;
+
   // Sends notification of a changed preference. This needs to be called by
   // a ScopedUserPrefUpdate if a DictionaryValue or ListValue is changed.
   void ReportUserPrefChanged(const std::string& key);
 
   // Sets the value for this pref path in the user pref store and informs the
   // PrefNotifier of the change.
   void SetUserPrefValue(const std::string& path, base::Value* new_value);
 
   // Load preferences from storage, attempting to diagnose and handle errors.
   // This should only be called from the constructor.
@@ skipping 18 matching lines @@
 
   // Local cache of registered Preference objects. The pref_registry_
   // is authoritative with respect to what the types and default values
   // of registered preferences are.
   mutable PreferenceMap prefs_map_;
 
   DISALLOW_COPY_AND_ASSIGN(PrefService);
 };
 
 #endif  // COMPONENTS_PREFS_PREF_SERVICE_H_