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

components/prefs/default_pref_store.cc

Index: components/prefs/default_pref_store.cc
diff --git a/components/prefs/default_pref_store.cc b/components/prefs/default_pref_store.cc
index 79867e95774b43b0b381e762a73701f4d7de272e..ed401899c871a1bd11e7289979183261e60e6029 100644
--- a/components/prefs/default_pref_store.cc
+++ b/components/prefs/default_pref_store.cc
@@ -30,13 +30,13 @@ bool DefaultPrefStore::HasObservers() const {
 }
 
 void DefaultPrefStore::SetDefaultValue(const std::string& key,
-                                       scoped_ptr<Value> value) {
+                                       std::unique_ptr<Value> value) {
   DCHECK(!GetValue(key, NULL));
   prefs_.SetValue(key, std::move(value));
 }
 
 void DefaultPrefStore::ReplaceDefaultValue(const std::string& key,
-                                           scoped_ptr<Value> value) {
+                                           std::unique_ptr<Value> value) {
   const Value* old_value = NULL;
   GetValue(key, &old_value);
   bool notify = !old_value->Equals(value.get());