Change MessageService to use ProfileKeyedAPI.

chrome/browser/extensions/extension_system.h

Index: chrome/browser/extensions/extension_system.h
diff --git a/chrome/browser/extensions/extension_system.h b/chrome/browser/extensions/extension_system.h
index d5d38c89e0e50f6be5245d952f5b00058d485afb..413dc552e7234fb95439625c1ed3119df93a94b6 100644
--- a/chrome/browser/extensions/extension_system.h
+++ b/chrome/browser/extensions/extension_system.h
@@ -106,9 +106,6 @@ class ExtensionSystem : public ProfileKeyedService {
   // The LazyBackgroundTaskQueue is created at startup.
   virtual LazyBackgroundTaskQueue* lazy_background_task_queue() = 0;
 
-  // The MessageService is created at startup.
-  virtual MessageService* message_service() = 0;
-
   // The EventRouter is created at startup.
   virtual EventRouter* event_router() = 0;
 
@@ -179,7 +176,6 @@ class ExtensionSystemImpl : public ExtensionSystem {
   virtual LazyBackgroundTaskQueue* lazy_background_task_queue()
       OVERRIDE;  // shared
   virtual ExtensionInfoMap* info_map() OVERRIDE;  // shared
-  virtual MessageService* message_service() OVERRIDE;  // shared
   virtual EventRouter* event_router() OVERRIDE;  // shared
   virtual RulesRegistryService* rules_registry_service()
       OVERRIDE;  // shared
@@ -228,7 +224,6 @@ class ExtensionSystemImpl : public ExtensionSystem {
     Blacklist* blacklist();
     ExtensionInfoMap* info_map();
     LazyBackgroundTaskQueue* lazy_background_task_queue();
-    MessageService* message_service();
     EventRouter* event_router();
     ExtensionWarningService* warning_service();
 
@@ -247,7 +242,6 @@ class ExtensionSystemImpl : public ExtensionSystem {
     // MessageService and EventRouter.
     scoped_ptr<LazyBackgroundTaskQueue> lazy_background_task_queue_;
     scoped_ptr<EventRouter> event_router_;
-    scoped_ptr<MessageService> message_service_;
     scoped_ptr<NavigationObserver> navigation_observer_;
     scoped_refptr<UserScriptMaster> user_script_master_;
     // Blacklist depends on ExtensionPrefs.