Remove content::NotificationObserver dependency from most Prefs code.

base/prefs/public/pref_init_observer.h

Index: base/prefs/public/pref_init_observer.h
diff --git a/base/prefs/public/pref_init_observer.h b/base/prefs/public/pref_init_observer.h
new file mode 100644
index 0000000000000000000000000000000000000000..5c1cd0b81764c5139870562baa21f03b29bfb1a9
--- /dev/null
+++ b/base/prefs/public/pref_init_observer.h
@@ -0,0 +1,18 @@
+// 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.
+
+#ifndef BASE_PREFS_PUBLIC_PREF_INIT_OBSERVER_H_
+#define BASE_PREFS_PUBLIC_PREF_INIT_OBSERVER_H_
+
+#include <string>
+
+class PrefServiceBase;
+
+class PrefInitObserver {
+ public:

[Mattias Nissler (ping if slow), 2012/10/30 13:37:07]

Please add a comment here explaining when this gets called and what it is good
for.

+  virtual void OnInitializationCompleted(PrefServiceBase* pref_service,
+                                         bool succeeded) = 0;
+};
+
+#endif  // BASE_PREFS_PUBLIC_PREF_INIT_OBSERVER_H_