Remove PrefServiceSimple, replacing it with PrefService and PrefRegistrySimple.

chrome/browser/prefs/pref_registry.h

Index: chrome/browser/prefs/pref_registry.h
diff --git a/chrome/browser/prefs/pref_registry.h b/chrome/browser/prefs/pref_registry.h
new file mode 100644
index 0000000000000000000000000000000000000000..327f98733f8549398997ee8765737f80b8e3fc4c
--- /dev/null
+++ b/chrome/browser/prefs/pref_registry.h
@@ -0,0 +1,75 @@
+// 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 CHROME_BROWSER_PREFS_PREF_REGISTRY_H_
+#define CHROME_BROWSER_PREFS_PREF_REGISTRY_H_
+
+#include "base/callback.h"
+#include "base/memory/ref_counted.h"
+#include "base/prefs/pref_value_map.h"
+
+namespace base {
+class Value;
+}
+
+class DefaultPrefStore;
+class PrefStore;
+
+// Preferences need to be registered with a type and default value
+// before they are used.
+//
+// The way you use a PrefRegistry is that you register all required
+// preferences on it (via one of its subclasses), then pass it as a
+// construction parameter to PrefService.
+//
+// Currently, registrations after constructing the PrefService will
+// also work, but this is being deprecated.
+class PrefRegistry : public base::RefCounted<PrefRegistry> {
+ public:
+  typedef PrefValueMap::const_iterator const_iterator;
+  typedef base::Callback<void(const char*, base::Value*)> RegistrationCallback;
+  typedef base::Callback<void(const char*)> UnregistrationCallback;
+
+  PrefRegistry();
+
+  // Gets the registered defaults.
+  scoped_refptr<PrefStore> defaults();
+
+  // Allows iteration over defaults.
+  const_iterator begin() const;
+  const_iterator end() const;
+
+  // Exactly one callback can be set for each of two events:
+  // Registration and unregistration. If either is set, the callback
+  // will be invoked each time registration and/or unregistration has
+  // been performed on this object.
+  //
+  // Calling either of these methods after a callback has already been
+  // set will make the object forget the previous callback and use the
+  // new one instead.
+  void SetRegistrationCallback(const RegistrationCallback& callback);
+  void SetUnregistrationCallback(const UnregistrationCallback& callback);
+
+  // Unregisters a preference. This is going away soon.
+  virtual void DeprecatedUnregisterPreference(const char* path);
+
+ protected:
+  friend class base::RefCounted<PrefRegistry>;
+  virtual ~PrefRegistry();
+
+  // TODO(joi): Temporary until we have PrefRegistrySyncable.
+  friend class PrefServiceSyncable;
+
+  // Used by subclasses to register a default value for a preference.
+  void RegisterPreference(const char* path, base::Value* default_value);
+
+ private:
+  RegistrationCallback registration_callback_;
+  UnregistrationCallback unregistration_callback_;
+  scoped_refptr<DefaultPrefStore> defaults_;
+
+  DISALLOW_COPY_AND_ASSIGN(PrefRegistry);
+};
+
+#endif  // CHROME_BROWSER_PREFS_PREF_REGISTRY_H_