Convert //ios from scoped_ptr to std::unique_ptr.

ios/chrome/browser/ui/webui/flags_ui.cc

Index: ios/chrome/browser/ui/webui/flags_ui.cc
diff --git a/ios/chrome/browser/ui/webui/flags_ui.cc b/ios/chrome/browser/ui/webui/flags_ui.cc
index 9d48d271e788f46145418a8995933a5623794480..c72ce345afe2deadb2ab890d763e46321a7217b5 100644
--- a/ios/chrome/browser/ui/webui/flags_ui.cc
+++ b/ios/chrome/browser/ui/webui/flags_ui.cc
@@ -113,7 +113,7 @@ class FlagsDOMHandler : public web::WebUIIOSMessageHandler {
   void HandleResetAllFlags(const base::ListValue* args);
 
  private:
-  scoped_ptr<flags_ui::FlagsStorage> flags_storage_;
+  std::unique_ptr<flags_ui::FlagsStorage> flags_storage_;
   flags_ui::FlagAccess access_;
   bool experimental_features_requested_;
 
@@ -158,8 +158,8 @@ void FlagsDOMHandler::HandleRequestExperimentalFeatures(
 
   base::DictionaryValue results;
 
-  scoped_ptr<base::ListValue> supported_features(new base::ListValue);
-  scoped_ptr<base::ListValue> unsupported_features(new base::ListValue);
+  std::unique_ptr<base::ListValue> supported_features(new base::ListValue);
+  std::unique_ptr<base::ListValue> unsupported_features(new base::ListValue);
   GetFlagFeatureEntries(flags_storage_.get(), access_, supported_features.get(),
                         unsupported_features.get());
   results.Set(flags_ui::kSupportedFeatures, supported_features.release());