Removing PrefObserver usage, batch 4.

chrome/browser/extensions/api/managed_mode/managed_mode_api.h

Index: chrome/browser/extensions/api/managed_mode/managed_mode_api.h
diff --git a/chrome/browser/extensions/api/managed_mode/managed_mode_api.h b/chrome/browser/extensions/api/managed_mode/managed_mode_api.h
index 7df8db7e6ca27d9b10f9c163bbe05e55513c36a1..d61dbb6f95f19fbea2185727a7ab7400364d8a3b 100644
--- a/chrome/browser/extensions/api/managed_mode/managed_mode_api.h
+++ b/chrome/browser/extensions/api/managed_mode/managed_mode_api.h
@@ -9,7 +9,6 @@
 #define CHROME_BROWSER_EXTENSIONS_API_MANAGED_MODE_MANAGED_MODE_API_H_
 
 #include "base/prefs/public/pref_change_registrar.h"
-#include "base/prefs/public/pref_observer.h"
 #include "chrome/browser/extensions/extension_function.h"
 #include "content/public/browser/notification_observer.h"
 
@@ -17,16 +16,14 @@ class Profile;
 
 namespace extensions {
 
-class ExtensionManagedModeEventRouter : public PrefObserver {
+class ExtensionManagedModeEventRouter {
  public:
   explicit ExtensionManagedModeEventRouter(Profile* profile);
   virtual ~ExtensionManagedModeEventRouter();
 
-  // PrefObserver implementation:
-  virtual void OnPreferenceChanged(PrefServiceBase* service,
-                                   const std::string& pref_name) OVERRIDE;
-
  private:
+  void OnInManagedModeChanged();
+
   PrefChangeRegistrar registrar_;
   Profile* profile_;