Split PrefService into PrefService, PrefServiceSimple and PrefServiceSyncable.

chrome/browser/prefs/pref_service_simple.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.
+
+#ifndef CHROME_BROWSER_PREFS_PREF_SERVICE_SIMPLE_H_
+#define CHROME_BROWSER_PREFS_PREF_SERVICE_SIMPLE_H_
+
+#include "chrome/browser/prefs/pref_service.h"
+
+// A simple PrefService implementation.
+class PrefServiceSimple : public PrefService {

[Mattias Nissler (ping if slow), 2012/12/19 19:50:22]

Thinking more about these names: I'm wondering whether this would be easier to
understand for people if we named this LocalStatePrefService and the one used
for profile prefs ProfilePrefService, respectively. In general, I'm in favor of
naming a class based on what it does instead of what it's used for, but in this
case we might reduce confusing amongst developers significantly (what exactly is
Simple? Does Syncable imply everything gets synced?). WDYT?

[Jói, 2012/12/20 16:30:31]

I think Syncable implies "can be synced" not "is synced" so as far as a name for
a service that allows synced prefs I think it is fine.

Depending on what we do, this probably goes away anyway, at least
PrefServiceSimple probably goes away or at least is hidden and used only by the
browser_prefs code and the various RegisterPrefs functions, and everywhere else
you primarily use PrefService, sometimes PrefServiceSyncable depending on your
needs.

[Mattias Nissler (ping if slow), 2012/12/21 13:09:31]

Yes, makes sense. Material for follow-up changes then.

+ public:
+  void RegisterBooleanPref(const char* path, bool default_value);
+  void RegisterIntegerPref(const char* path, int default_value);
+  void RegisterDoublePref(const char* path, double default_value);
+  void RegisterStringPref(const char* path, const std::string& default_value);
+  void RegisterFilePathPref(const char* path, const FilePath& default_value);
+  void RegisterListPref(const char* path);
+  void RegisterDictionaryPref(const char* path);
+  void RegisterListPref(const char* path, base::ListValue* default_value);
+  void RegisterDictionaryPref(
+      const char* path, base::DictionaryValue* default_value);
+  void RegisterInt64Pref(const char* path,
+                         int64 default_value);
+ protected:
+  // Only use ChromePrefServiceFactory to create initialized PrefServiceSimple
+  // objects.
+  PrefServiceSimple();

[Mattias Nissler (ping if slow), 2012/12/20 13:41:52]

needs a virtual dtor

[Jói, 2012/12/20 16:30:31]

Done, also added DISALLOW_COPY_AND_ASSIGN.

+
+  // Constructs objects.
+  friend class ChromePrefServiceFactory;
+  friend class PrefServiceMockBuilder;
+};
+
+#endif  // CHROME_BROWSER_PREFS_PREF_SERVICE_SIMPLE_H_