Switch SupportsUserData uses to use unique_ptr.

chrome/browser/infobars/infobar_service.h

Index: chrome/browser/infobars/infobar_service.h
diff --git a/chrome/browser/infobars/infobar_service.h b/chrome/browser/infobars/infobar_service.h
index e5dec851586260ae3e22603290ae108d696eac62..d04bdc42f76353222cc0b77e0a4c5cacb2847402 100644
--- a/chrome/browser/infobars/infobar_service.h
+++ b/chrome/browser/infobars/infobar_service.h
@@ -30,6 +30,8 @@ class InfoBarService : public infobars::InfoBarManager,
                        public content::WebContentsObserver,
                        public content::WebContentsUserData<InfoBarService> {
  public:
+  ~InfoBarService() override;
+
   static infobars::InfoBarDelegate::NavigationDetails
       NavigationDetailsFromLoadCommittedDetails(
           const content::LoadCommittedDetails& details);
@@ -59,7 +61,6 @@ class InfoBarService : public infobars::InfoBarManager,
   friend class content::WebContentsUserData<InfoBarService>;
 
   explicit InfoBarService(content::WebContents* web_contents);
-  ~InfoBarService() override;
 
   // InfoBarManager:
   int GetActiveEntryID() override;