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

components/prefs/value_map_pref_store.cc

Index: components/prefs/value_map_pref_store.cc
diff --git a/components/prefs/value_map_pref_store.cc b/components/prefs/value_map_pref_store.cc
index fe2c80893db34f77d86a3bf0a1891b0623bc8273..15a0eb1e92b1d99e9e0535ad3b56294b6fc6652b 100644
--- a/components/prefs/value_map_pref_store.cc
+++ b/components/prefs/value_map_pref_store.cc
@@ -30,7 +30,7 @@ bool ValueMapPrefStore::HasObservers() const {
 }
 
 void ValueMapPrefStore::SetValue(const std::string& key,
-                                 scoped_ptr<base::Value> value,
+                                 std::unique_ptr<base::Value> value,
                                  uint32_t flags) {
   if (prefs_.SetValue(key, std::move(value)))
     FOR_EACH_OBSERVER(Observer, observers_, OnPrefValueChanged(key));
@@ -52,7 +52,7 @@ void ValueMapPrefStore::ReportValueChanged(const std::string& key,
 }
 
 void ValueMapPrefStore::SetValueSilently(const std::string& key,
-                                         scoped_ptr<base::Value> value,
+                                         std::unique_ptr<base::Value> value,
                                          uint32_t flags) {
   prefs_.SetValue(key, std::move(value));
 }