Use underscores to separate words in filenames in webkitpy.

third_party/WebKit/Tools/Scripts/webkitpy/tool/webkit_patch_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.system.outputcapture import OutputCapture
+from webkitpy.common.system.output_capture import OutputCapture
 from webkitpy.tool.webkit_patch import WebKitPatch
 
 
 class WebKitPatchTest(unittest.TestCase):
 
     def test_split_args_basic(self):
         self.assertEqual(
             WebKitPatch._split_command_name_from_args(['--global-option', 'command', '--option', 'arg']),
             ('command', ['--global-option', '--option', 'arg']))
 
@@ skipping 28 matching lines @@
         tool = WebKitPatch('path')
         try:
             tool.main(['tool', '--help'])
         except SystemExit:
             pass  # optparse calls sys.exit after showing help.
         finally:
             out, err, logs = oc.restore_output()
         self.assertTrue(out.startswith('Usage: '))
         self.assertEqual('', err)
         self.assertEqual('', logs)