Remove several unneeded modules from webkitpy.common.

Tools/Scripts/webkitpy/layout_tests/port/mock_drt_unittest.py

 # Copyright (C) 2011 Google Inc. All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 # notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 # copyright notice, this list of conditions and the following disclaimer
@@ skipping 10 matching lines @@
 # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 """Unit tests for MockDRT."""
 
+import io
 import sys
 import unittest
 
-from webkitpy.common import newstringio
 from webkitpy.common.system.systemhost_mock import MockSystemHost
 from webkitpy.layout_tests.port import mock_drt
 from webkitpy.layout_tests.port import port_testcase
 from webkitpy.layout_tests.port import test
 from webkitpy.layout_tests.port.factory import PortFactory
 from webkitpy.tool import mocktool
 
 
 mock_options = mocktool.MockOptions(configuration='Release')
 
@@ skipping 75 matching lines @@
 
     def assertTest(self, test_name, pixel_tests, expected_checksum=None, drt_output=None, host=None, expected_text=None):
         port_name = 'test'
         host = host or MockSystemHost()
         test.add_unit_tests_to_mock_filesystem(host.filesystem)
         port = PortFactory(host).get(port_name)
         drt_input, drt_output = self.make_input_output(port, test_name,
             pixel_tests, expected_checksum, drt_output, drt_input=None, expected_text=expected_text)
 
         args = ['--dump-render-tree', '--platform', port_name, '-']
-        stdin = newstringio.StringIO(drt_input)
-        stdout = newstringio.StringIO()
-        stderr = newstringio.StringIO()
+        stdin = io.BytesIO(drt_input)
+        stdout = io.BytesIO()
+        stderr = io.BytesIO()
         options, args = mock_drt.parse_options(args)
 
         drt = self.make_drt(options, args, host, stdin, stdout, stderr)
         res = drt.run()
 
         self.assertEqual(res, 0)
 
-        # We use the StringIO.buflist here instead of getvalue() because
-        # the StringIO might be a mix of unicode/ascii and 8-bit strings.
-        self.assertEqual(stdout.buflist, drt_output)
+        self.assertEqual(stdout.getvalue(), ''.join(drt_output))
         self.assertEqual(stderr.getvalue(), '#EOF\n')
 
     def test_main(self):
         host = MockSystemHost()
         test.add_unit_tests_to_mock_filesystem(host.filesystem)
-        stdin = newstringio.StringIO()
-        stdout = newstringio.StringIO()
-        stderr = newstringio.StringIO()
+        stdin = io.BytesIO()
+        stdout = io.BytesIO()
+        stderr = io.BytesIO()
         res = mock_drt.main(['--dump-render-tree', '--platform', 'test', '-'],
                             host, stdin, stdout, stderr)
         self.assertEqual(res, 0)
         self.assertEqual(stdout.getvalue(), '')
         self.assertEqual(stderr.getvalue(), '')
         self.assertEqual(host.filesystem.written_files, {})
 
     def test_pixeltest_passes(self):
         # This also tests that we handle HTTP: test URLs properly.
         self.assertTest('http/tests/passes/text.html', True)
@@ skipping 31 matching lines @@
         self.assertTest('passes/audio.html', pixel_tests=True,
                         drt_output=['Content-Type: audio/wav\n',
                          'Content-Transfer-Encoding: base64\n',
                          'YXVkaW8td2F2',
                          '\n',
                          '#EOF\n',
                          '#EOF\n'])
 
     def test_virtual(self):
         self.assertTest('virtual/passes/text.html', True)