Add ManagedUserSettingsService and a SupervisedUserPrefStore using it.

chrome/browser/managed_mode/supervised_user_pref_store.h

Index: chrome/browser/managed_mode/supervised_user_pref_store.h
diff --git a/chrome/browser/managed_mode/supervised_user_pref_store.h b/chrome/browser/managed_mode/supervised_user_pref_store.h
new file mode 100644
index 0000000000000000000000000000000000000000..11e03ad9023258b24cb7698872c0b86b042737cb
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+++ b/chrome/browser/managed_mode/supervised_user_pref_store.h
@@ -0,0 +1,48 @@
+// Copyright 2013 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_MANAGED_MODE_SUPERVISED_USER_PREF_STORE_H_

[Pam (message me for reviews), 2013/09/03 10:45:32]

Didn't we decide to keep all the code named with Managed User instead of
Supervised User?

[Bernhard Bauer, 2013/09/03 10:53:43]

That created confusion in PrefValueStore, where we have managed preferences,
user preferences, and then managed user preferences, which are not related to
the former two.

I'm happy about other suggestions; One possibility would be to keep the term
"supervised user" in pure prefs code (i.e. base/prefs), and only use "managed
user" in managed_mode?

[bartfab (slow), 2013/09/03 11:16:07]

My vote goes to using "supervised user" in all new code. That way, there is a
single term going forward. And that term is consistent with the UI. Existing
code can slowly switch over to the new naming as it gets obsoleted and
refactored.

This is what we did for public sessions (formerly known as public accounts) and
it worked well for us.

+#define CHROME_BROWSER_MANAGED_MODE_SUPERVISED_USER_PREF_STORE_H_
+
+#include "base/memory/scoped_ptr.h"
+#include "base/observer_list.h"
+#include "base/prefs/pref_store.h"
+#include "chrome/browser/managed_mode/managed_users.h"
+
+namespace base {
+class DictionaryValue;
+class Value;
+}
+
+class ManagedUserSettingsService;
+class PrefValueMap;
+
+// A PrefStore that gets its values from managed user settings via the
+// ManagedUserSettingsService passed in at construction.
+class SupervisedUserPrefStore : public PrefStore {
+ public:
+  SupervisedUserPrefStore(
+      ManagedUserSettingsService* managed_user_settings_service);
+
+  // PrefStore overrides:
+  virtual bool GetValue(const std::string& key,
+                        const base::Value** value) const OVERRIDE;
+  virtual void AddObserver(PrefStore::Observer* observer) OVERRIDE;
+  virtual void RemoveObserver(PrefStore::Observer* observer) OVERRIDE;
+  virtual bool HasObservers() const OVERRIDE;
+  virtual bool IsInitializationComplete() const OVERRIDE;
+
+ private:
+  virtual ~SupervisedUserPrefStore();
+
+  void OnNewSettingsAvailable(const base::DictionaryValue* settings);
+
+  base::WeakPtrFactory<SupervisedUserPrefStore> weak_ptr_factory_;
+
+  scoped_ptr<PrefValueMap> prefs_;
+
+  ObserverList<PrefStore::Observer, true> observers_;
+};
+
+#endif  // CHROME_BROWSER_MANAGED_MODE_SUPERVISED_USER_PREF_STORE_H_