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

tools/perf/measurements/rasterize_and_record_micro.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
 import sys
 import time
 
 from telemetry.core.util import TimeoutException
 from telemetry.page import page_measurement
+from telemetry.page import page_test
 
 class RasterizeAndRecordMicro(page_measurement.PageMeasurement):
   def __init__(self):
     super(RasterizeAndRecordMicro, self).__init__('', True)
     self._compositing_features_enabled = False
 
   def AddCommandLineOptions(self, parser):
     parser.add_option('--start-wait-time', dest='start_wait_time',
                       default=2,
                       help='Wait time before the benchmark is started ' +
@@ skipping 21 matching lines @@
         '--enable-threaded-compositing',
         '--enable-gpu-benchmarking'
     ])
 
   def DidStartBrowser(self, browser):
     # TODO(vmpstr): Remove this temporary workaround when reference build has
     # been updated to branch 1713 or later.
     backend = browser._browser_backend # pylint: disable=W0212
     if (not hasattr(backend, 'chrome_branch_number') or
         (sys.platform != 'android' and backend.chrome_branch_number < 1713)):
-      return
+      raise page_test.TestNotSupportedOnPlatformFailure(
+          'rasterize_and_record_micro requires Chrome branch 1713 '
+          'or later. Skipping measurement.')
 
     # Check if the we actually have threaded forced compositing enabled.
     system_info = browser.GetSystemInfo()
     if (system_info.gpu.feature_status
         and system_info.gpu.feature_status.get(
             'compositing', None) == 'enabled_force_threaded'):
       self._compositing_features_enabled = True
 
   def MeasurePage(self, page, tab, results):
+    # Throw an exception if threaded forced compositing is not enabled.
     if not self._compositing_features_enabled:
-      logging.warning('Warning: RasterizeAndRecordMicro requires forced, '
-                      'threaded compositing and Chrome branch 1713 or newer.')
-      return
+      raise page_test.TestNotSupportedOnPlatformFailure(
+          'Compositing feature status unknown or not '+
+          'forced and threaded. Skipping measurement.')
 
     try:
       tab.WaitForJavaScriptExpression("document.readyState == 'complete'", 10)
     except TimeoutException:
       pass
     time.sleep(float(self.options.start_wait_time))
 
     record_repeat = self.options.record_repeat
     rasterize_repeat = self.options.rasterize_repeat
     # Enqueue benchmark
@@ skipping 47 matching lines @@
       results.Add('pixels_rasterized_with_non_solid_color', 'pixels',
           pixels_rasterized_with_non_solid_color)
       results.Add('pixels_rasterized_as_opaque', 'pixels',
           pixels_rasterized_as_opaque)
       results.Add('total_layers', 'count', total_layers)
       results.Add('total_picture_layers', 'count', total_picture_layers)
       results.Add('total_picture_layers_with_no_content', 'count',
           total_picture_layers_with_no_content)
       results.Add('total_picture_layers_off_screen', 'count',
           total_picture_layers_off_screen)
-