Revert 170483 - Remove PrefObserver usages, batch 12.

chrome/browser/ui/cocoa/browser_window_cocoa.h

Index: chrome/browser/ui/cocoa/browser_window_cocoa.h
===================================================================
--- chrome/browser/ui/cocoa/browser_window_cocoa.h	(revision 170518)
+++ chrome/browser/ui/cocoa/browser_window_cocoa.h	(working copy)
@@ -8,6 +8,7 @@
 #include "base/memory/scoped_nsobject.h"
 #include "base/memory/weak_ptr.h"
 #include "base/prefs/public/pref_change_registrar.h"
+#include "base/prefs/public/pref_observer.h"
 #include "chrome/browser/bookmarks/bookmark_model.h"
 #include "chrome/browser/extensions/extension_keybinding_registry.h"
 #include "chrome/browser/ui/browser_window.h"
@@ -31,6 +32,7 @@
 
 class BrowserWindowCocoa :
     public BrowserWindow,
+    public PrefObserver,
     public extensions::ExtensionKeybindingRegistry::Delegate {
  public:
   BrowserWindowCocoa(Browser* browser,
@@ -144,6 +146,10 @@
                                 const gfx::Rect& rect) OVERRIDE;
   virtual void ShowAvatarBubbleFromAvatarButton() OVERRIDE;
 
+  // Overridden from NotificationObserver
+  virtual void OnPreferenceChanged(PrefServiceBase* service,
+                                   const std::string& pref_name) OVERRIDE;
+
   // Overridden from ExtensionKeybindingRegistry::Delegate:
   virtual extensions::ActiveTabPermissionGranter*
       GetActiveTabPermissionGranter() OVERRIDE;
@@ -158,7 +164,6 @@
   virtual void DestroyBrowser() OVERRIDE;
 
  private:
-  virtual void OnShowBookmarkBarChanged();
   NSWindow* window() const;  // Accessor for the (current) |NSWindow|.
 
   PrefChangeRegistrar pref_change_registrar_;