Remove content::NotificationObserver dependency from most Prefs code.

chrome/browser/profiles/profile_impl.h

Index: chrome/browser/profiles/profile_impl.h
diff --git a/chrome/browser/profiles/profile_impl.h b/chrome/browser/profiles/profile_impl.h
index 7389d37def64d5bf2dc3f89210df7124f747f3fe..efb05ad93043a1d8bd26e7df8d02347978076abb 100644
--- a/chrome/browser/profiles/profile_impl.h
+++ b/chrome/browser/profiles/profile_impl.h
@@ -14,6 +14,7 @@
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/prefs/public/pref_change_registrar.h"
+#include "base/prefs/public/pref_init_observer.h"
 #include "base/timer.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/profiles/profile_impl_io_data.h"
@@ -22,6 +23,7 @@
 
 class NetPrefObserver;
 class PrefService;
+class PrefServiceBase;
 class PromoResourceService;
 class SSLConfigServiceManager;
 
@@ -43,7 +45,9 @@ class ExtensionSystem;
 
 // The default profile implementation.
 class ProfileImpl : public Profile,
-                    public content::NotificationObserver {
+                    public content::NotificationObserver,
+                    public PrefObserver,
+                    public PrefInitObserver {
  public:
   // Value written to prefs when the exit type is EXIT_NORMAL. Public for tests.
   static const char* const kPrefExitTypeNormal;
@@ -127,6 +131,14 @@ class ProfileImpl : public Profile,
                        const content::NotificationSource& source,
                        const content::NotificationDetails& details) OVERRIDE;
 
+  // PrefObserver implementation.
+  virtual void OnPreferenceChanged(PrefServiceBase* service,
+                                   const std::string& pref_name) OVERRIDE;
+
+  // PrefInitObserver implementation.
+  virtual void OnInitializationCompleted(PrefServiceBase* pref_service,
+                                         bool succeeded) OVERRIDE;
+
  private:
   friend class Profile;
   FRIEND_TEST_ALL_PREFIXES(StartupBrowserCreatorTest,