Unittest for pushing the restart logic into start browser.

content/test/gpu/gpu_tests/gpu_integration_test.py

Index: content/test/gpu/gpu_tests/gpu_integration_test.py
diff --git a/content/test/gpu/gpu_tests/gpu_integration_test.py b/content/test/gpu/gpu_tests/gpu_integration_test.py
index e32cc538bb4516d83f78b0e9cc7b8ad50eeaf61a..c415e15c768a7a3f18f757383ead237921961ffa 100644
--- a/content/test/gpu/gpu_tests/gpu_integration_test.py
+++ b/content/test/gpu/gpu_tests/gpu_integration_test.py
@@ -5,6 +5,7 @@
 import logging
 
 from telemetry.testing import serially_executed_browser_test_case
+from telemetry.util import screenshot
 
 from gpu_tests import exception_formatter
 from gpu_tests import gpu_test_expectations
@@ -29,22 +30,34 @@ class GpuIntegrationTest(
     for test_name, url, args in cls.GenerateGpuTests(options):
       yield test_name, (url, test_name, args)
 
-  def _RestartBrowser(self, reason):
+  @classmethod
+  def StartBrowser(cls):
     for x in range(0, 3):
       try:
-        restart_attempt = ('Restarting browser %d time due to '
-          % (x + 1))
-        logging.warning(restart_attempt + reason)
-        self.StopBrowser()
-        self.SetBrowserOptions(self._finder_options)
-        self.StartBrowser()
-        self.tab = self.browser.tabs[0]
+        restart = 'Starting browser %d time' % (x + 1)

[Ken Russell (switch to Gerrit), 2016/08/03 22:21:39]

Could you add " (of 3)" to the end? e.g. "Starting browser, attempt 1 of 3" or
similar. Thanks.

[eyaich, 2016/08/04 01:53:10]

Done.

+        logging.warning(restart)
+        super(GpuIntegrationTest, cls).StartBrowser()

[Ken Russell (switch to Gerrit), 2016/08/03 22:21:39]

How about adding a call to a no-op method called something like
"_PossiblyFailForTesting()" or similar here? Then the test subclass can have a
little per-test state that raises an exception in its override the first two
times. Would that help with the unit test?

[eyaich, 2016/08/04 01:53:10]

The problem with calling a super method here (unless I am missing something, I
am new to python) is that it knows nothing about the test subclass.  I could
easily manufacture something in the overriden method in the test class, but that
only gets called once.  Each time this restarts, it only calls the
super.StartBrowser method and catches any exceptions here, it doesn't return to
the test subclass until the three attempts are over.

         return
       except Exception:
-        # If we are on the last try and there is an exception raise it
+        # If we are on the last try and there is an exception take a screenshot
+        # to try and capture more about the browser failure and raise
         if x == 2:
+          url = screenshot.TryCaptureScreenShotAndUploadToCloudStorage(
+            cls.platform)
+          if url is not None:
+            logging.info("GpuIntegrationTest screenshot of browser failure " +
+              "located at " + url)
+          else:
+            logging.warning("GpuIntegrationTest unable to take screenshot")
           raise
 
+  def _RestartBrowser(self, reason):
+    logging.warning('Restarting browser due to '+ reason)
+    self.StopBrowser()
+    self.SetBrowserOptions(self._finder_options)
+    self.StartBrowser()
+    self.tab = self.browser.tabs[0]
+
   def _RunGpuTest(self, url, test_name, args):
     temp_page = _EmulatedPage(url, test_name)
     expectations = self.__class__.GetExpectations()