Remove PrefObserver usages, batch 12.

chrome/browser/ui/ash/launcher/chrome_launcher_controller_per_browser.h

Index: chrome/browser/ui/ash/launcher/chrome_launcher_controller_per_browser.h
diff --git a/chrome/browser/ui/ash/launcher/chrome_launcher_controller_per_browser.h b/chrome/browser/ui/ash/launcher/chrome_launcher_controller_per_browser.h
index 49e1883d9ea3894b16b1067cf729a101b6cbf148..5ef6ad13c2d787bbb309baa22952351e4a0b1a7f 100644
--- a/chrome/browser/ui/ash/launcher/chrome_launcher_controller_per_browser.h
+++ b/chrome/browser/ui/ash/launcher/chrome_launcher_controller_per_browser.h
@@ -18,7 +18,6 @@
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/prefs/public/pref_change_registrar.h"
-#include "base/prefs/public/pref_observer.h"
 #include "chrome/browser/extensions/extension_prefs.h"
 #include "chrome/browser/prefs/pref_service_observer.h"
 #include "chrome/browser/ui/ash/app_sync_ui_state_observer.h"
@@ -61,7 +60,6 @@ class ChromeLauncherControllerPerBrowser
       public ash::ShellObserver,
       public ChromeLauncherController,
       public content::NotificationObserver,
-      public PrefObserver,
       public PrefServiceObserver,
       public AppSyncUIStateObserver {
  public:
@@ -237,10 +235,6 @@ class ChromeLauncherControllerPerBrowser
                        const content::NotificationSource& source,
                        const content::NotificationDetails& details) OVERRIDE;
 
-  // Overridden from PrefObserver:
-  virtual void OnPreferenceChanged(PrefServiceBase* service,
-                                   const std::string& pref_name) OVERRIDE;
-
   // Overridden from ash::ShellObserver:
   virtual void OnShelfAlignmentChanged() OVERRIDE;