Restart browser after expected failure.

content/test/gpu/gpu_tests/gpu_integration_test.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 logging
 
 from telemetry.testing import serially_executed_browser_test_case
 
 from gpu_tests import exception_formatter
 from gpu_tests import gpu_test_expectations
@@ skipping 51 matching lines @@
         # the detail to the console.
         exception_formatter.PrintFormattedException()
         # This failure might have been caused by a browser or renderer
         # crash, so restart the browser to make sure any state doesn't
         # propagate to the next test iteration.
         self._RestartBrowser('unexpected test failure')
         raise
       elif expectation == 'fail':
         msg = 'Expected exception while running %s' % test_name
         exception_formatter.PrintFormattedException(msg=msg)
+        # Even though this is a known failure, the browser might still
+        # be in a bad state; for example, certain kinds of timeouts
+        # will affect the next test. Restart the browser to prevent
+        # these kinds of failures propagating to the next test.
+        self._RestartBrowser('expected test failure')
         return
       if expectation != 'flaky':
         logging.warning(
           'Unknown expectation %s while handling exception for %s',
           expectation, test_name)
         raise
       # Flaky tests are handled here.
       num_retries = expectations.GetFlakyRetriesForPage(
         self.browser, temp_page)
       if not num_retries:
@@ skipping 54 matching lines @@
 
   def setUp(self):
     try:
       self.tab = self.browser.tabs[0]
     except Exception:
       # restart the browser to make sure a failure in a test doesn't
       # propagate to the next test iteration.
       logging.exception("Failure during browser startup")
       self._RestartBrowser('failure in setup')
       raise