Revert of [Telemetry] Do not close tab connections if the tab is already gone.

tools/telemetry/telemetry/page/page_run_end_to_end_unittest.py

Index: tools/telemetry/telemetry/page/page_run_end_to_end_unittest.py
diff --git a/tools/telemetry/telemetry/page/page_run_end_to_end_unittest.py b/tools/telemetry/telemetry/page/page_run_end_to_end_unittest.py
index 88b770d7a31a239050af3ddbe731dc9adf01501b..6d4d8e58af1865834ab8de7c34347c09e1002888 100644
--- a/tools/telemetry/telemetry/page/page_run_end_to_end_unittest.py
+++ b/tools/telemetry/telemetry/page/page_run_end_to_end_unittest.py
@@ -5,8 +5,6 @@
 import os
 import unittest
 import shutil
-import sys
-import StringIO
 import tempfile
 
 from telemetry import benchmark
@@ -24,7 +22,7 @@
 from telemetry.unittest_util import options_for_unittests
 from telemetry.unittest_util import system_stub
 from telemetry.user_story import user_story_runner
-from telemetry.util import exception_formatter
+from telemetry.util import exception_formatter as exception_formatter_module
 from unittest_data.page_sets import example_domain
 
 
@@ -75,14 +73,11 @@
   return [run for run in results.all_page_runs if run.ok or run.skipped]
 
 
-def CaptureStderr(func, output_buffer):
-  def wrapper(*args, **kwargs):
-    original_stderr, sys.stderr = sys.stderr, output_buffer
-    try:
-      return func(*args, **kwargs)
-    finally:
-      sys.stderr = original_stderr
-  return wrapper
+class FakeExceptionFormatterModule(object):
+  @staticmethod
+  def PrintFormattedException(
+      exception_class=None, exception=None, tb=None, msg=None):
+    pass
 
 
 # TODO: remove test cases that use real browsers and replace with a
@@ -93,22 +88,14 @@
 
   def setUp(self):
     self._user_story_runner_logging_stub = None
-    self._formatted_exception_buffer = StringIO.StringIO()
-    self._original_formatter = exception_formatter.PrintFormattedException
-
-  def CaptureFormattedException(self):
-    exception_formatter.PrintFormattedException = CaptureStderr(
-        exception_formatter.PrintFormattedException,
-        self._formatted_exception_buffer)
+
+  def SuppressExceptionFormatting(self):
+    user_story_runner.exception_formatter = FakeExceptionFormatterModule
     self._user_story_runner_logging_stub = system_stub.Override(
-        user_story_runner, ['logging'])
-
-  @property
-  def formatted_exception(self):
-    return self._formatted_exception_buffer.getvalue()
+      user_story_runner, ['logging'])
 
   def RestoreExceptionFormatter(self):
-    exception_formatter.PrintFormattedException = self._original_formatter
+    user_story_runner.exception_formatter = exception_formatter_module
     if self._user_story_runner_logging_stub:
       self._user_story_runner_logging_stub.Restore()
       self._user_story_runner_logging_stub = None
@@ -117,7 +104,7 @@
     self.RestoreExceptionFormatter()
 
   def testRaiseBrowserGoneExceptionFromRestartBrowserBeforeEachPage(self):
-    self.CaptureFormattedException()
+    self.SuppressExceptionFormatting()
     ps = page_set.PageSet()
     expectations = test_expectations.TestExpectations()
     ps.pages.append(page_module.Page(
@@ -151,10 +138,9 @@
     self.assertEquals(2, test.run_count)
     self.assertEquals(1, len(GetSuccessfulPageRuns(results)))
     self.assertEquals(1, len(results.failures))
-    self.assertEquals('', self.formatted_exception)
 
   def testNeedsBrowserRestartAfterEachPage(self):
-    self.CaptureFormattedException()
+    self.SuppressExceptionFormatting()
     ps = page_set.PageSet()
     expectations = test_expectations.TestExpectations()
     ps.pages.append(page_module.Page(
@@ -183,10 +169,9 @@
     user_story_runner.Run(test, ps, expectations, options, results)
     self.assertEquals(2, len(GetSuccessfulPageRuns(results)))
     self.assertEquals(2, test.browser_starts)
-    self.assertEquals('', self.formatted_exception)
 
   def testHandlingOfCrashedTabWithExpectedFailure(self):
-    self.CaptureFormattedException()
+    self.SuppressExceptionFormatting()
     ps = page_set.PageSet()
     expectations = test_expectations.TestExpectations()
     expectations.Fail('chrome://crash')
@@ -201,18 +186,14 @@
     user_story_runner.Run(DummyTest(), ps, expectations, options, results)
     self.assertEquals(1, len(GetSuccessfulPageRuns(results)))
     self.assertEquals(0, len(results.failures))
-    self.assertIn('DevtoolsTargetCrashException', self.formatted_exception)
-    # Check that only one exception is raised.
-    self.assertEquals(1, self.formatted_exception.count('Traceback'))
 
   def testCredentialsWhenLoginFails(self):
-    self.CaptureFormattedException()
+    self.SuppressExceptionFormatting()
     credentials_backend = StubCredentialsBackend(login_return_value=False)
     did_run = self.runCredentialsTest(credentials_backend)
     assert credentials_backend.did_get_login == True
     assert credentials_backend.did_get_login_no_longer_needed == False
     assert did_run == False
-    self.assertEquals('', self.formatted_exception)
 
   def testCredentialsWhenLoginSucceeds(self):
     credentials_backend = StubCredentialsBackend(login_return_value=True)
@@ -503,6 +484,7 @@
       shutil.rmtree(options.output_dir)
 
   def _RunPageTestThatRaisesAppCrashException(self, test, max_failures):
+    self.SuppressExceptionFormatting()
     class TestPage(page_module.Page):
       def RunNavigateSteps(self, _):
         raise exceptions.AppCrashException
@@ -522,7 +504,6 @@
     return results
 
   def testSingleTabMeansCrashWillCauseFailureValue(self):
-    self.CaptureFormattedException()
     class SingleTabTest(page_test.PageTest):
       # Test is not multi-tab because it does not override TabForPage.
       def ValidateAndMeasurePage(self, *_):
@@ -532,11 +513,9 @@
     results = self._RunPageTestThatRaisesAppCrashException(test, max_failures=1)
     self.assertEquals([], GetSuccessfulPageRuns(results))
     self.assertEquals(2, len(results.failures))  # max_failures + 1
-    self.assertEquals('', self.formatted_exception)
 
   @decorators.Enabled('has tabs')
   def testMultipleTabsMeansCrashRaises(self):
-    self.CaptureFormattedException()
     class MultipleTabsTest(page_test.PageTest):
       # Test *is* multi-tab because it overrides TabForPage.
       def TabForPage(self, page, browser):
@@ -547,9 +526,6 @@
     test = MultipleTabsTest()
     with self.assertRaises(page_test.MultiTabTestAppCrashError):
       self._RunPageTestThatRaisesAppCrashException(test, max_failures=1)
-    self.assertIn('AppCrashException', self.formatted_exception)
-    # Check that only one exception is raised.
-    self.assertEquals(1, self.formatted_exception.count('Traceback'))
 
   def testWebPageReplay(self):
     ps = example_domain.ExampleDomainPageSet()