telemetry: handle tests that are not supported on a platform.

tools/perf/measurements/rasterize_and_record_unittest.py

 # Copyright 2013 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 measurements import rasterize_and_record
 from telemetry import test
 from telemetry.core import wpr_modes
 from telemetry.page import page_measurement_unittest_base
+from telemetry.page import page_test
 from telemetry.unittest import options_for_unittests
 
 
 class RasterizeAndRecordUnitTest(
       page_measurement_unittest_base.PageMeasurementUnitTestBase):
   """Smoke test for rasterize_and_record measurement
 
      Runs rasterize_and_record measurement on a simple page and verifies that
      all metrics were added to the results. The test is purely functional,
      i.e. it only checks if the metrics are present and non-zero.
   """
 
   def setUp(self):
     self._options = options_for_unittests.GetCopy()
     self._options.browser_options.wpr_mode = wpr_modes.WPR_OFF
     self._options.raster_record_repeat = 1
     self._options.start_wait_time = 0.0
     self._options.stop_wait_time = 2.0
 
   @test.Disabled
   def testRasterizeAndRecord(self):
     ps = self.CreatePageSetFromFileInUnittestDataDir('blank.html')
     measurement = rasterize_and_record.RasterizeAndRecord()
-    results = self.RunMeasurement(measurement, ps, options=self._options)
+    try:
+      results = self.RunMeasurement(measurement, ps, options=self._options)
+    except page_test.TestNotSupportedOnPlatformFailure as failure:
+      logging.warning(str(failure))
+      return
     self.assertEquals(0, len(results.failures))
 
     rasterize_time = results.FindAllPageSpecificValuesNamed('rasterize_time')
     self.assertEquals(len(rasterize_time), 1)
     self.assertGreater(rasterize_time[0].GetRepresentativeNumber(), 0)
 
     record_time = results.FindAllPageSpecificValuesNamed('record_time')
     self.assertEquals(len(record_time), 1)
     self.assertGreater(record_time[0].GetRepresentativeNumber(), 0)
 
     rasterized_pixels = results.FindAllPageSpecificValuesNamed(
         'rasterized_pixels')
     self.assertEquals(len(rasterized_pixels), 1)
     self.assertGreater(rasterized_pixels[0].GetRepresentativeNumber(), 0)
 
     recorded_pixels = results.FindAllPageSpecificValuesNamed('recorded_pixels')
     self.assertEquals(len(recorded_pixels), 1)
     self.assertGreater(recorded_pixels[0].GetRepresentativeNumber(), 0)