Move TestingPrefService to use unique_ptr<Value>

components/certificate_transparency/ct_policy_manager_unittest.cc

Index: components/certificate_transparency/ct_policy_manager_unittest.cc
diff --git a/components/certificate_transparency/ct_policy_manager_unittest.cc b/components/certificate_transparency/ct_policy_manager_unittest.cc
index 6abc261cbb5a601cd7b8e0e57bc4d13d407df92d..e535f98baa3526fca6cc5eac328dc385fda46460 100644
--- a/components/certificate_transparency/ct_policy_manager_unittest.cc
+++ b/components/certificate_transparency/ct_policy_manager_unittest.cc
@@ -20,12 +20,13 @@ namespace certificate_transparency {
 
 namespace {
 
-base::ListValue* ListValueFromStrings(const std::vector<const char*>& strings) {
+std::unique_ptr<base::ListValue> ListValueFromStrings(
+    const std::vector<const char*>& strings) {
   std::unique_ptr<base::ListValue> result(new base::ListValue);
   for (auto* const str : strings) {
     result->AppendString(str);
   }
-  return result.release();
+  return result;
 }
 
 class CTPolicyManagerTest : public ::testing::Test {