Add ManagedUserSettingsService and a SupervisedUserPrefStore using it.

chrome/browser/managed_mode/managed_user_constants.h

Index: chrome/browser/managed_mode/managed_user_constants.h
diff --git a/chrome/browser/managed_mode/managed_user_constants.h b/chrome/browser/managed_mode/managed_user_constants.h
new file mode 100644
index 0000000000000000000000000000000000000000..c96ea6f7f01f34477ee65dbe56b2c0b7bce54b8b
--- /dev/null
+++ b/chrome/browser/managed_mode/managed_user_constants.h
@@ -0,0 +1,19 @@
+// 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_MANAGED_USER_CONSTANTS_H_
+#define CHROME_BROWSER_MANAGED_MODE_MANAGED_USER_CONSTANTS_H_
+
+namespace managed_users {
+
+extern const char kContentPackDefaultFilteringBehavior[];

[Pam (message me for reviews), 2013/09/04 10:21:47]

Comments describing these constants, please, especially since the filename
doesn't say they're all settings anymore. And even if it did, "setting" isn't
very specific; mention what subsystem uses these as keys.

[Bernhard Bauer, 2013/09/04 11:56:19]

Done.

+extern const char kContentPackManualBehaviorHosts[];
+extern const char kContentPackManualBehaviorURLs[];
+extern const char kForceSafeSearch[];
+extern const char kSigninAllowed[];
+extern const char kUserName[];
+
+}  // managed_users
+
+#endif  // CHROME_BROWSER_MANAGED_MODE_MANAGED_USER_CONSTANTS_H_