Remove dependency of PrefSyncableService on Profile.

chrome/browser/prefs/pref_service_syncable.h

Index: chrome/browser/prefs/pref_service_syncable.h
diff --git a/chrome/browser/prefs/pref_service_syncable.h b/chrome/browser/prefs/pref_service_syncable.h
index da52017911454d014c83796fee049b9e098056fa..8f8bbf0e5adfec6ffc2f439ab99706ae5394dd7f 100644
--- a/chrome/browser/prefs/pref_service_syncable.h
+++ b/chrome/browser/prefs/pref_service_syncable.h
@@ -5,13 +5,15 @@
 #ifndef CHROME_BROWSER_PREFS_PREF_SERVICE_SYNCABLE_H_
 #define CHROME_BROWSER_PREFS_PREF_SERVICE_SYNCABLE_H_
 
+#include "base/callback_forward.h"
 #include "base/prefs/pref_service.h"
 #include "chrome/browser/prefs/pref_model_associator.h"
 #include "chrome/browser/prefs/synced_pref_observer.h"
 #include "components/pref_registry/pref_registry_syncable.h"
 
+class OverlayUserPrefStore;
+class PrefModelAssociatorClient;
 class PrefServiceSyncableObserver;
-class Profile;
 
 namespace syncer {
 class SyncableService;
@@ -22,36 +24,31 @@ class SyncableService;
 // this PrefService.
 class PrefServiceSyncable : public PrefService {
  public:
-  // PrefServiceSyncable is a PrefService with added integration for
-  // sync, and knowledge of how to create an incognito
-  // PrefService. For code that does not need to know about the sync
-  // integration, you should use only the plain PrefService type.
-  //
-  // For this reason, Profile does not expose an accessor for the
-  // PrefServiceSyncable type. Instead, you can use the utilities
-  // below to retrieve the PrefServiceSyncable (or its incognito
-  // version) from a Profile.
-  static PrefServiceSyncable* FromProfile(Profile* profile);
-  static PrefServiceSyncable* IncognitoFromProfile(Profile* profile);
-
   // You may wish to use PrefServiceFactory or one of its subclasses
   // for simplified construction.
-  PrefServiceSyncable(
-      PrefNotifierImpl* pref_notifier,
-      PrefValueStore* pref_value_store,
-      PersistentPrefStore* user_prefs,
-      user_prefs::PrefRegistrySyncable* pref_registry,
-      base::Callback<void(PersistentPrefStore::PrefReadError)>
-          read_error_callback,
-      bool async);
+  PrefServiceSyncable(PrefNotifierImpl* pref_notifier,
+                      PrefValueStore* pref_value_store,
+                      PersistentPrefStore* user_prefs,
+                      user_prefs::PrefRegistrySyncable* pref_registry,
+                      base::Callback<void(PersistentPrefStore::PrefReadError)>
+                          read_error_callback,
+                      bool async);
   ~PrefServiceSyncable() override;
 
+  // Sets the PrefModelAssociatorClient that control special treatment of
+  // some preferences during synchronisation. Must be called before starting
+  // the synchronisation.
+  void SetPrefModelAssociatorClient(
+      PrefModelAssociatorClient* pref_model_associator_client);

[gab, 2015/09/10 14:15:09]

Feels this should be a constructor input (since it's (1) not optional, (2) not
set multiple times, and (3) there is no cyclic dependency forcing it to be
created after).

This would also allow other two classes depending on it to take it in there
constructor (since this class builds them).

It would also prevent programming mistakes (i.e. forgetting to set it on a
subclass, etc.).

I'd expect it to be set on PrefServiceSyncableFactory (just like other set_foo()
calls on PrefServiceFactory) and then passed to the PrefServiceSyncable()
constructor in CreateSyncable().

ref:
https://code.google.com/p/chromium/codesearch#chromium/src/chrome/browser/pre...

(reviewing further I see you already added it to the factory, so it's only a
made of changing from a setter to a constructor argument IMO unless I'm missing
a use case?)

+
   // Creates an incognito copy of the pref service that shares most pref stores
   // but uses a fresh non-persistent overlay for the user pref store and an
   // individual extension pref store (to cache the effective extension prefs for
   // incognito windows).

[gab, 2015/09/10 14:15:09]

Update comment.

   PrefServiceSyncable* CreateIncognitoPrefService(
-      PrefStore* incognito_extension_prefs);
+      PrefStore* incognito_extension_prefs,
+      const base::Callback<void(OverlayUserPrefStore*)>&
+          incognito_pref_created_cb);
 
   // Returns true if preferences state has synchronized with the remote
   // preferences. If true is returned it can be assumed the local preferences
@@ -104,6 +101,7 @@ class PrefServiceSyncable : public PrefService {
 
   PrefModelAssociator pref_sync_associator_;
   PrefModelAssociator priority_pref_sync_associator_;
+  PrefModelAssociatorClient* pref_model_associator_client_;
 
   base::ObserverList<PrefServiceSyncableObserver> observer_list_;