In WPT importer, abort if there are exportable-but-not-yet-exported commits.

third_party/WebKit/Tools/Scripts/webkitpy/w3c/test_importer_unittest.py

 # Copyright 2016 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import unittest
 
 from webkitpy.common.host_mock import MockHost
 from webkitpy.common.system.executive_mock import MockExecutive
 from webkitpy.w3c.test_importer import TestImporter
 
 
 class TestImporterTest(unittest.TestCase):
 
+    def test_abort_on_exportable_commits(self):
+        importer = TestImporter(MockHost())
+        importer.exportable_but_not_exported_commits = lambda _: ['aaaa']
+        return_code = importer.main(['wpt'])
+        self.assertEqual(return_code, 1)
+
     def test_update_test_expectations(self):
         host = MockHost()
         host.filesystem.files['/mock-checkout/third_party/WebKit/LayoutTests/TestExpectations'] = (
             'Bug(test) some/test/a.html [ Failure ]\n'
             'Bug(test) some/test/b.html [ Failure ]\n'
             'Bug(test) some/test/c.html [ Failure ]\n')
         host.filesystem.files['/mock-checkout/third_party/WebKit/LayoutTests/VirtualTestSuites'] = '[]'
         host.filesystem.files['/mock-checkout/third_party/WebKit/LayoutTests/new/a.html'] = ''
         host.filesystem.files['/mock-checkout/third_party/WebKit/LayoutTests/new/b.html'] = ''
         importer = TestImporter(host)
@@ skipping 90 matching lines @@
                     '--work',
                     '--tests-root',
                     '/mock-checkout/third_party/WebKit/LayoutTests/external/wpt'
                 ],
                 [
                     'git',
                     'add',
                     '/mock-checkout/third_party/WebKit/LayoutTests/external/wpt/MANIFEST.json'
                 ]
             ])