Switch base::Value typemapping to be by value instead of by unique_ptr.

components/safe_json/utility/safe_json_parser_mojo_impl.cc

Index: components/safe_json/utility/safe_json_parser_mojo_impl.cc
diff --git a/components/safe_json/utility/safe_json_parser_mojo_impl.cc b/components/safe_json/utility/safe_json_parser_mojo_impl.cc
index 1595192008e1725804a0c790a2ec3e0195367272..6d25a3b27d61df7f707117e7586bbd526ecc567c 100644
--- a/components/safe_json/utility/safe_json_parser_mojo_impl.cc
+++ b/components/safe_json/utility/safe_json_parser_mojo_impl.cc
@@ -32,9 +32,9 @@ void SafeJsonParserMojoImpl::Parse(const std::string& json,
   std::unique_ptr<base::Value> value = base::JSONReader::ReadAndReturnError(
       json, base::JSON_PARSE_RFC, &error_code, &error);
   if (value) {
-    callback.Run(std::move(value), base::nullopt);
+    callback.Run(*value, base::nullopt);
   } else {
-    callback.Run(nullptr, base::make_optional(std::move(error)));
+    callback.Run(base::nullopt, base::make_optional(std::move(error)));
   }
 }