Convert //components/user_prefs from scoped_ptr to std::unique_ptr

components/user_prefs/tracked/interceptable_pref_filter.cc

Index: components/user_prefs/tracked/interceptable_pref_filter.cc
diff --git a/components/user_prefs/tracked/interceptable_pref_filter.cc b/components/user_prefs/tracked/interceptable_pref_filter.cc
index cfe081d986813b1267375ab631485082070135bb..f3ee3c7187c6c838c7701c44a17d8a1f9aa94d40 100644
--- a/components/user_prefs/tracked/interceptable_pref_filter.cc
+++ b/components/user_prefs/tracked/interceptable_pref_filter.cc
@@ -15,7 +15,7 @@ InterceptablePrefFilter::~InterceptablePrefFilter() {
 
 void InterceptablePrefFilter::FilterOnLoad(
     const PostFilterOnLoadCallback& post_filter_on_load_callback,
-    scoped_ptr<base::DictionaryValue> pref_store_contents) {
+    std::unique_ptr<base::DictionaryValue> pref_store_contents) {
   if (filter_on_load_interceptor_.is_null()) {
     FinalizeFilterOnLoad(post_filter_on_load_callback,
                          std::move(pref_store_contents), false);