message: [XLA] Change type to appease GPU builds.
diff: @@ -18,7 +18,7 @@ limitations under the License.
  GTEST_API_ int main(int argc, char** argv) {
  std::vector<tensorflow::Flag> flag_list;
  xla::legacy_flags::AppendDebugOptionsFlags(&flag_list);
  - string usage = tensorflow::Flags::Usage(argv[0], flag_list);
  + auto usage = tensorflow::Flags::Usage(argv[0], flag_list);
  if (!tensorflow::Flags::Parse(&argc, argv, flag_list)) {
  LOG(ERROR) << "\n" << usage;
  return 2;
  