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

tools/perf/measurements/rasterize_and_record.py

 # Copyright (c) 2012 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 metrics import rendering_stats
 from telemetry.page import page_measurement
+from telemetry.page import page_test
 import telemetry.core.timeline.bounds as timeline_bounds
 from telemetry.core.timeline.model import MarkerMismatchError
 from telemetry.core.timeline.model import MarkerOverlapError
 
 TIMELINE_MARKER = 'RasterizeAndRecord'
 
 
 class RasterizeAndRecord(page_measurement.PageMeasurement):
   def __init__(self):
     super(RasterizeAndRecord, self).__init__('', True)
@@ skipping 32 matching lines @@
 
   def DidStartBrowser(self, browser):
     # 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):
-    # Exit if threaded forced compositing is not enabled.
+    # Throw and exception if threaded forced compositing is not enabled.
     if (not self._compositing_features_enabled):
-      logging.warning('Warning: compositing feature status unknown or not '+
-                      'forced and threaded. Skipping measurement.')
-      sys.exit(0)
+      raise page_test.TestNotSupportedOnPlatformFailure(
+          'Compositing feature status unknown or not '+
+          'forced and threaded. Skipping measurement.')
 
     # Rasterize only what's visible.
     tab.ExecuteJavaScript(
         'chrome.gpuBenchmarking.setRasterizeOnlyVisibleContent();')
 
     # Wait until the page has loaded and come to a somewhat steady state.
     # Needs to be adjusted for every device (~2 seconds for workstation).
     time.sleep(float(self.options.start_wait_time))
 
     # Render one frame before we start gathering a trace. On some pages, the
@@ skipping 35 matching lines @@
     stats = rendering_stats.RenderingStats(renderer_process, timeline_ranges)
 
     results.Add('rasterize_time', 'ms',
                 max(stats.rasterize_time))
     results.Add('record_time', 'ms',
                 max(stats.record_time))
     results.Add('rasterized_pixels', 'pixels',
                 max(stats.rasterized_pixel_count))
     results.Add('recorded_pixels', 'pixels',
                 max(stats.recorded_pixel_count))