Remove content::NotificationObserver dependency from most Prefs code.

chrome/browser/ui/views/tabs/browser_tab_strip_controller.h

Index: chrome/browser/ui/views/tabs/browser_tab_strip_controller.h
diff --git a/chrome/browser/ui/views/tabs/browser_tab_strip_controller.h b/chrome/browser/ui/views/tabs/browser_tab_strip_controller.h
index 0ed9504919c08dd8f15825ec8dd5e7b89b20f1c5..a33fcf02b956ee7e8bcb8cbd8b10b5c5bd4e7c57 100644
--- a/chrome/browser/ui/views/tabs/browser_tab_strip_controller.h
+++ b/chrome/browser/ui/views/tabs/browser_tab_strip_controller.h
@@ -8,12 +8,12 @@
 #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/ui/search/search_model_observer.h"
 #include "chrome/browser/ui/search/toolbar_search_animator_observer.h"
 #include "chrome/browser/ui/tabs/hover_tab_selector.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/browser/ui/views/tabs/tab_strip_controller.h"
-#include "content/public/browser/notification_observer.h"
 
 class BaseTab;
 class Browser;
@@ -31,7 +31,7 @@ class WebContents;
 class BrowserTabStripController
     : public TabStripController,
       public TabStripModelObserver,
-      public content::NotificationObserver,
+      public PrefObserver,
       public chrome::search::SearchModelObserver,
       public chrome::search::ToolbarSearchAnimatorObserver {
  public:
@@ -114,10 +114,9 @@ class BrowserTabStripController
       content::WebContents* web_contents) OVERRIDE;
   virtual void OnToolbarSeparatorChanged() OVERRIDE {}
 
-  // content::NotificationObserver implementation:
-  virtual void Observe(int type,
-                       const content::NotificationSource& source,
-                       const content::NotificationDetails& details) OVERRIDE;
+  // PrefObserver implementation:
+  virtual void OnPreferenceChanged(PrefServiceBase* service,
+                                   const std::string& pref_name) OVERRIDE;
 
  protected:
   // The context in which SetTabRendererDataFromModel is being called.