Removing PrefObserver usage, batch 4.

chrome/browser/extensions/extension_service.h

Index: chrome/browser/extensions/extension_service.h
diff --git a/chrome/browser/extensions/extension_service.h b/chrome/browser/extensions/extension_service.h
index 1eb6603b27174a717af8f570f3462f0b8c5de0ba..a982488aaae1c86376a4f8dc727954034c4e124d 100644
--- a/chrome/browser/extensions/extension_service.h
+++ b/chrome/browser/extensions/extension_service.h
@@ -17,7 +17,6 @@
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "base/prefs/public/pref_change_registrar.h"
-#include "base/prefs/public/pref_observer.h"
 #include "base/string16.h"
 #include "chrome/browser/extensions/app_shortcut_manager.h"
 #include "chrome/browser/extensions/app_sync_bundle.h"
@@ -140,8 +139,7 @@ class ExtensionServiceInterface : public syncer::SyncableService {
 class ExtensionService
     : public ExtensionServiceInterface,
       public extensions::ExternalProviderInterface::VisitorInterface,
-      public content::NotificationObserver,
-      public PrefObserver {
+      public content::NotificationObserver {
  public:
   // The name of the directory inside the profile where extensions are
   // installed to.
@@ -633,10 +631,6 @@ class ExtensionService
                        const content::NotificationSource& source,
                        const content::NotificationDetails& details) OVERRIDE;
 
-  // PrefObserver
-  virtual void OnPreferenceChanged(PrefServiceBase* service,
-                                   const std::string& pref_name) OVERRIDE;
-
   // Whether there are any apps installed. Component apps are not included.
   bool HasApps() const;
 
@@ -710,6 +704,8 @@ class ExtensionService
                          syncer::ModelType type)
       const;
 
+  void OnExtensionInstallPrefChanged();
+
   // Handles setting the extension specific values in |extension_sync_data| to
   // the current system.
   // Returns false if the changes were not completely applied and need to be