Handle multiple signin_internal_uis by using a linked_ptr

components/signin/core/browser/about_signin_internals.h

Index: components/signin/core/browser/about_signin_internals.h
diff --git a/components/signin/core/browser/about_signin_internals.h b/components/signin/core/browser/about_signin_internals.h
index f3458219fa0f40210268a67eaa9d95ffa3403a89..61a89c131bf9ca85ae850f23ea23545372c4c1bb 100644
--- a/components/signin/core/browser/about_signin_internals.h
+++ b/components/signin/core/browser/about_signin_internals.h
@@ -8,6 +8,7 @@
 #include <map>
 #include <string>
 
+#include "base/memory/linked_ptr.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/observer_list.h"
 #include "base/values.h"
@@ -44,7 +45,7 @@ class AboutSigninInternals
 
     // Notification that the cookie accounts are ready to be displayed.
     virtual void OnCookieAccountsFetched(
-        scoped_ptr<base::DictionaryValue> info) = 0;
+        linked_ptr<base::DictionaryValue> info) = 0;
   };
 
   AboutSigninInternals(ProfileOAuth2TokenService* token_service,