Ported pixel_test to new gpu_integration_test harness.

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 75df3cbaec20bc4786ad851953674e8940781cc6..3c4e98d3d4b10d574ce1517231bb019d821c347a 100644
--- a/content/test/gpu/gpu_tests/gpu_integration_test.py
+++ b/content/test/gpu/gpu_tests/gpu_integration_test.py
@@ -51,12 +51,13 @@ class GpuIntegrationTest(
             logging.warning("GpuIntegrationTest unable to take screenshot")
           raise
 
-  def _RestartBrowser(self, reason):
+  @classmethod
+  def _RestartBrowser(cls, reason):
     logging.warning('Restarting browser due to '+ reason)
-    self.StopBrowser()
-    self.SetBrowserOptions(self._finder_options)
-    self.StartBrowser()
-    self.tab = self.browser.tabs[0]
+    cls.StopBrowser()
+    cls.SetBrowserOptions(cls._finder_options)
+    cls.StartBrowser()
+    cls.tab = cls.browser.tabs[0]
 
   def _RunGpuTest(self, url, test_name, *args):
     temp_page = _EmulatedPage(url, test_name)
@@ -158,12 +159,16 @@ class GpuIntegrationTest(
     # Do not call this directly. Call GetExpectations where necessary.
     raise NotImplementedError
 
-  def setUp(self):
+  @classmethod
+  def _EnsureTabIsAvailable(cls):
     try:
-      self.tab = self.browser.tabs[0]
+      cls.tab = cls.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')
+      cls._RestartBrowser('failure in setup')
       raise
+
+  def setUp(self):
+    self._EnsureTabIsAvailable()