Extend time capping to run_tests_matrix scripts

tools/run_tests/run_tests_matrix.py

@@ -377,6 +377,9 @@ if __name__ == "__main__":
   argp.add_argument('-n', '--runs_per_test', default=1, type=_runs_per_test_type,
                     help='How many times to run each tests. >1 runs implies ' +
                     'omitting passing test from the output & reports.')
+  argp.add_argument('--max_time', default=-1, type=int,
+                    help='Maximum amount of time to run tests for' +
+                         '(other tests will be skipped)')
   args = argp.parse_args()
 
   extra_args = []
@@ -388,6 +391,8 @@ if __name__ == "__main__":
     extra_args.append('-n')
     extra_args.append('%s' % args.runs_per_test)
     extra_args.append('--quiet_success')
+  if args.max_time > 0:
+    extra_args.extend(('--max_time', '%d' % args.max_time))
 
   all_jobs = _create_test_jobs(extra_args=extra_args, inner_jobs=args.inner_jobs) + \
              _create_portability_test_jobs(extra_args=extra_args, inner_jobs=args.inner_jobs)