ResourceMapping-related code is no longer used.Moreover, there is an
ASan related-error in ResourceMappingDarwin:
https://logs.chromium.org/logs/fuchsia/buildbucket/cr-buildbucket.appspot.com/8940466063445826656/+/steps/test_results/0/steps/s___out_release-x64_host_tests_dart_schema_tests/0/logs/stdio/0