Respect `machineFormat` in package-mode.

pkg/analyzer_cli/test/driver_test.dart

Index: pkg/analyzer_cli/test/driver_test.dart
diff --git a/pkg/analyzer_cli/test/driver_test.dart b/pkg/analyzer_cli/test/driver_test.dart
index 244788c174717685d6a90a69170657f627f9781f..516ee058f20e17e54288e4e5d04487c83d312bc6 100644
--- a/pkg/analyzer_cli/test/driver_test.dart
+++ b/pkg/analyzer_cli/test/driver_test.dart
@@ -252,8 +252,7 @@ linter:
               outSink.toString(),
               contains(
                   "[error] This function declares a return type of 'int'"));
-          expect(outSink.toString(),
-              contains("1 error and 1 warning found."));
+          expect(outSink.toString(), contains("1 error and 1 warning found."));
         });
 
         test('language', () {
@@ -280,12 +279,24 @@ linter:
           // Should not be made fatal by `--fatal-warnings`.
           expect(outSink.toString(),
               contains("[warning] The function 'baz' is not defined"));
-          expect(outSink.toString(),
-              contains("1 error and 1 warning found."));
+          expect(outSink.toString(), contains("1 error and 1 warning found."));
         });
       });
     });
 
+    group('package-mode', () {
+      // Shared driver command.
+      var doDrive = () => drive('data/options_tests_project/test_file.dart',
+          args: ['--package-mode', '--machine'],
+          options: 'data/options_tests_project/.analysis_options');
+
+      test('no stats', () {
+        doDrive();
+        // Should not print stat summary.
+        expect(outSink.toString(), isEmpty);
+      });
+    });
+
 //TODO(pq): fix to be bot-friendly (sdk#25258).
 //    group('in temp directory', () {
 //      Directory savedCurrentDirectory;
@@ -348,8 +359,6 @@ linter:
 //      });
 //    });
   });
-
-
 }
 
 const emptyOptionsFile = 'data/empty_options.yaml';