Change more base::ListValue methods to use std::unique_ptr.

chrome/browser/extensions/extension_management_test_util.cc

Index: chrome/browser/extensions/extension_management_test_util.cc
diff --git a/chrome/browser/extensions/extension_management_test_util.cc b/chrome/browser/extensions/extension_management_test_util.cc
index 3fcc0603e1323dc5fd7714bcec805d34d5bab078..b87364543791b1525284e634dd5e867458ff3984 100644
--- a/chrome/browser/extensions/extension_management_test_util.cc
+++ b/chrome/browser/extensions/extension_management_test_util.cc
@@ -7,6 +7,7 @@
 #include <string>
 #include <utility>
 
+#include "base/memory/ptr_util.h"
 #include "components/crx_file/id_util.h"
 #include "components/policy/core/common/configuration_policy_provider.h"
 #include "components/policy/core/common/mock_configuration_policy_provider.h"
@@ -232,7 +233,8 @@ void ExtensionManagementPrefUpdaterBase::AddStringToList(
     list_value = new base::ListValue();
     pref_->Set(path, list_value);
   }
-  CHECK(list_value->AppendIfNotPresent(new base::StringValue(str)));
+  CHECK(
+      list_value->AppendIfNotPresent(base::MakeUnique<base::StringValue>(str)));
 }
 
 void ExtensionManagementPrefUpdaterBase::RemoveStringFromList(