Fix typos in num_failures_by_type for json results.

mojo/tools/run_mojo_python_tests.py

Index: mojo/tools/run_mojo_python_tests.py
diff --git a/mojo/tools/run_mojo_python_tests.py b/mojo/tools/run_mojo_python_tests.py
index 778a575f138f2b032f8b9a512fff042329a039d3..da9ab63f5923fa346ac34969e9c20e5eea2f7468 100755
--- a/mojo/tools/run_mojo_python_tests.py
+++ b/mojo/tools/run_mojo_python_tests.py
@@ -49,7 +49,7 @@ def main():
     if pylib_dir not in sys.path:
       sys.path.append(pylib_dir)
     suite = unittest.TestSuite()
-    for test_name in args:
+    for test_name in args.tests:
       suite.addTests(loader.loadTestsFromName(test_name))
   else:
     suite = loader.discover(pylib_dir, pattern='*_unittest.py')
@@ -88,8 +88,8 @@ def _FullResults(suite, result, metadata):
   failed_test_names = _FailedTestNames(result)
 
   full_results['num_failures_by_type'] = {
-      'Failure': len(failed_test_names),
-      'Pass': len(all_test_names) - len(failed_test_names),
+      'FAIL': len(failed_test_names),
+      'PASS': len(all_test_names) - len(failed_test_names),
   }
 
   full_results['tests'] = {}