[Android] Prepare the test runner for @RetryOnFailure.

build/android/pylib/local/device/local_device_instrumentation_test_run.py

 # Copyright 2015 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 posixpath
 import re
 import time
 
@@ skipping 313 matching lines @@
       for l in output:
         logging.debug('  %s', l)
     if self._test_instance.coverage_directory:
       device.PullFile(coverage_directory,
           self._test_instance.coverage_directory)
       device.RunShellCommand('rm -f %s' % os.path.join(coverage_directory,
           '*'))
     return results
 
   #override
+  def _ShouldRetry(self, test):
+    if 'RetryOnFailure' in test.get('annotations', {}):
+      return True
+
+    # TODO(jbudorick): Remove this log message and switch the return value to
+    # False after tests have been annotated with @RetryOnFailure.
+    # See crbug.com/619055 for more details.
+    logging.warning('Default retries are being phased out. crbug.com/619055')
+    return True
+
+  #override
   def _ShouldShard(self):
     return True
 
   @classmethod
   def _GetTimeoutScaleFromAnnotations(cls, annotations):
     try:
       return int(annotations.get('TimeoutScale', 1))
     except ValueError as e:
       logging.warning("Non-integer value of TimeoutScale ignored. (%s)", str(e))
       return 1
 
   @classmethod
   def _GetTimeoutFromAnnotations(cls, annotations, test_name):
     for k, v in TIMEOUT_ANNOTATIONS:
       if k in annotations:
         timeout = v
         break
     else:
       logging.warning('Using default 1 minute timeout for %s', test_name)
       timeout = 60
 
     timeout *= cls._GetTimeoutScaleFromAnnotations(annotations)
 
     return timeout