Fix IEDriver error on closing.

tools/testing/run_selenium.py

 #!/usr/bin/python
 
 # Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 #
 
 """Script to actually open a browser and perform the test, and reports back with
 the result. It uses Selenium WebDriver when possible for running the tests. It
 uses Selenium RC for Safari.
@@ skipping 194 matching lines @@
     raise Exception('Incompatible browser and platform combination.')
 
 def close_browser(browser):
   if browser is None:
     return
   if isinstance(browser, selenium.selenium):
     browser.stop()
     return
 
   # A timeout exception is thrown if nothing happens within the time limit.
-  if browser != 'chrome':
+  if (type(browser) is not selenium.webdriver.chrome.webdriver.WebDriver and
+      type(browser) is not selenium.webdriver.ie.webdriver.WebDriver):
     browser.close()
-  try:
-    browser.quit()
-  except selenium.common.exceptions.WebDriverException:
-    # TODO(efortuna): Figure out why this crashes.... and avoid?
-    pass
+  browser.quit()
 
 def report_results(mode, source):
   # TODO(vsm): Add a failure check for Dromaeo.
   if mode != 'correctness':
     # We're running a performance test.
     print source.encode('utf8')
     sys.stdout.flush()
     if 'NaN' in source:
       return 1
     else:
@@ skipping 97 matching lines @@
   browser = start_browser(browser_name, executable_path, html_out)
 
   try:
     output = run_test_in_browser(browser, html_out, timeout, mode)
     return report_results(mode, output)
   finally:
     close_browser(browser)
 
 if __name__ == "__main__":
   sys.exit(main(sys.argv))