Convert //chrome/browser/ui from scoped_ptr to std::unique_ptr

chrome/browser/ui/prefs/prefs_tab_helper.h

Index: chrome/browser/ui/prefs/prefs_tab_helper.h
diff --git a/chrome/browser/ui/prefs/prefs_tab_helper.h b/chrome/browser/ui/prefs/prefs_tab_helper.h
index f814ce12790a9ad5c7dce285d76be7de0e97698a..16a296e52ecd78d49c2d530982977897800230b2 100644
--- a/chrome/browser/ui/prefs/prefs_tab_helper.h
+++ b/chrome/browser/ui/prefs/prefs_tab_helper.h
@@ -58,9 +58,9 @@ class PrefsTabHelper : public content::NotificationObserver,
   content::WebContents* web_contents_;
   Profile* profile_;
   content::NotificationRegistrar registrar_;
-  scoped_ptr<base::CallbackList<void(void)>::Subscription>
+  std::unique_ptr<base::CallbackList<void(void)>::Subscription>
       style_sheet_subscription_;
-  scoped_ptr<ChromeZoomLevelPrefs::DefaultZoomLevelSubscription>
+  std::unique_ptr<ChromeZoomLevelPrefs::DefaultZoomLevelSubscription>
       default_zoom_level_subscription_;
   base::WeakPtrFactory<PrefsTabHelper> weak_ptr_factory_;