Splits shelf alignment and auto-hide behavior into two values, one

chrome/browser/prefs/pref_service.h

Index: chrome/browser/prefs/pref_service.h
diff --git a/chrome/browser/prefs/pref_service.h b/chrome/browser/prefs/pref_service.h
index a083cc92ed9f7a38b91b7d86f5a8dd099aa5ab92..6f4fba29b2cd412504fb2e2584faf018c5a553c6 100644
--- a/chrome/browser/prefs/pref_service.h
+++ b/chrome/browser/prefs/pref_service.h
@@ -16,6 +16,7 @@
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/observer_list.h"
 #include "base/threading/non_thread_safe.h"
 #include "chrome/browser/api/prefs/pref_service_base.h"
 
@@ -25,6 +26,7 @@ class PersistentPrefStore;
 class PrefModelAssociator;
 class PrefNotifier;
 class PrefNotifierImpl;
+class PrefServiceObserver;
 class PrefStore;
 class PrefValueStore;
 
@@ -128,6 +130,18 @@ class PrefService : public PrefServiceBase, public base::NonThreadSafe {
   // immediately (basically, during shutdown).
   void CommitPendingWrite();
 
+  void AddObserver(PrefServiceObserver* observer);
+  void RemoveObserver(PrefServiceObserver* observer);
+
+  // Returns true if preferences state has synchronized with the remote
+  // preferences. If true is returned it can be assumed the local preferences
+  // has applied changes from the remote preferences. The two may not be
+  // identical if a change is in flight (from either side).
+  bool HasSynced();

[sky, 2012/10/23 00:24:21]

I'm not the biggest fan of this name. If you have a better suggestion say it.

I'm also not the biggest fan of exposing HasSyncedChanged. If you prefer an
interface that PrefsModelAssociator uses (or a friend) say it.

+
+  // Invoked internally when the HasSynced() state changes.
+  void HasSyncedChanged();
+
   // PrefServiceBase implementation.
   virtual bool IsManagedPreference(const char* pref_name) const OVERRIDE;
   virtual bool IsUserModifiablePreference(const char* pref_name) const OVERRIDE;
@@ -343,6 +357,8 @@ class PrefService : public PrefServiceBase, public base::NonThreadSafe {
   // "forked" PrefService.
   bool pref_service_forked_;
 
+  ObserverList<PrefServiceObserver> observer_list_;
+
   DISALLOW_COPY_AND_ASSIGN(PrefService);
 };