sandwich: Properly detect page load failures

tools/android/loading/sandwich_runner.py

 # Copyright 2016 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 os
 import shutil
 import sys
 import tempfile
 
@@ skipping 29 matching lines @@
 _DEVTOOLS_TIMEOUT = 60
 
 # Categories to enable or disable for all traces collected. Disabled categories
 # are prefixed with '-'.
 _TRACING_CATEGORIES = [
   'blink',
   'blink.net',
   'blink.user_timing',
   'devtools.timeline',
   'java',
+  'navigation',
   'toplevel',
   'v8',
   '-cc',  # A lot of unnecessary events are enabled by default in "cc".
 ]
 
 TTFMP_ADDITIONAL_CATEGORIES = [
   'loading',
   'disabled-by-default-blink.debug.layout',
 ]
 
@@ skipping 12 matching lines @@
       int(dirname)
     except ValueError:
       continue
     shutil.rmtree(directory_path)
 
 
 class CacheOperation(object):
   CLEAR, SAVE, PUSH = range(3)
 
 
+class SandwichRunnerError(Exception):
+  pass
+
+
 class SandwichRunner(object):
   """Sandwich runner.
 
   This object is meant to be configured first and then run using the Run()
   method.
   """
   _ATTEMPT_COUNT = 3
   _STOP_DELAY_MULTIPLIER = 2
   _ABORT_RUN_TIMEOUT_SECONDS = 30 * 60
 
@@ skipping 110 matching lines @@
         if run_path is not None and self.record_video:
           device = self._chrome_ctl.GetDevice()
           if device is None:
             raise RuntimeError('Can only record video on a remote device.')
           video_recording_path = os.path.join(run_path, VIDEO_FILENAME)
           with device_setup.RemoteSpeedIndexRecorder(device, connection,
                                                      video_recording_path):
             trace = RecordTrace()
         else:
           trace = RecordTrace()
+        for event in trace.request_track.GetEvents():
+          if event.failed:
+            logging.warning(
+                'request to %s failed: %s', event.url, event.error_text)
+        if not trace.tracing_track.HasLoadingSucceeded():
+          raise SandwichRunnerError('Page load has failed.')
     if run_path is not None:
       trace_path = os.path.join(run_path, TRACE_FILENAME)
       trace.ToJsonFile(trace_path)
 
   def _RunInRetryLoop(self, repeat_id, perform_dry_run_before):
     """Attempts to run monitoring navigation.
 
     Args:
       repeat_id: Id of the run in the output directory.
       perform_dry_run_before: Whether it should do a dry run attempt before the
@@ skipping 134 matching lines @@
     if not os.path.isdir(repeat_dir):
       continue
     try:
       repeat_id = int(node_name)
     except ValueError:
       continue
     yield repeat_id, repeat_dir
     repeated_run_count += 1
   assert repeated_run_count > 0, ('Error: not a sandwich runner output '
                                   'directory: {}').format(runner_output_dir)