[Android] Add support for external sharding to the test runner.

build/android/pylib/instrumentation/instrumentation_test_instance.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 collections
 import copy
 import json
 import logging
 import os
 import pickle
@@ skipping 486 matching lines @@
 
     self._store_tombstones = False
     self._initializeTombstonesAttributes(args)
 
     self._should_save_logcat = None
     self._initializeLogAttributes(args)
 
     self._edit_shared_prefs = []
     self._initializeEditPrefsAttributes(args)
 
+    self._external_shard_index = args.test_launcher_shard_index
+    self._total_external_shards = args.test_launcher_total_shards
+
   def _initializeApkAttributes(self, args, error_func):
     if args.apk_under_test:
       apk_under_test_path = args.apk_under_test
       if not args.apk_under_test.endswith('.apk'):
         apk_under_test_path = os.path.join(
             constants.GetOutDirectory(), constants.SDK_BUILD_APKS_DIR,
             '%s.apk' % args.apk_under_test)
 
       # TODO(jbudorick): Move the realpath up to the argument parser once
       # APK-by-name is no longer supported.
@@ skipping 210 matching lines @@
 
   @property
   def driver_name(self):
     return self._driver_name
 
   @property
   def edit_shared_prefs(self):
     return self._edit_shared_prefs
 
   @property
+  def external_shard_index(self):
+    return self._external_shard_index
+
+  @property
   def flags(self):
     return self._flags
 
   @property
   def should_save_logcat(self):
     return self._should_save_logcat
 
   @property
   def package_info(self):
     return self._package_info
@@ skipping 35 matching lines @@
     return self._test_runner
 
   @property
   def test_runner_junit4(self):
     return self._test_runner_junit4
 
   @property
   def timeout_scale(self):
     return self._timeout_scale
 
+  @property
+  def total_external_shards(self):
+    return self._total_external_shards
+
   #override
   def TestType(self):
     return 'instrumentation'
 
   #override
   def SetUp(self):
     self._data_deps.extend(
         self._data_deps_delegate(self._runtime_deps_path))
 
   def GetDataDependencies(self):
@@ skipping 67 matching lines @@
 
   @staticmethod
   def GenerateTestResults(
       result_code, result_bundle, statuses, start_ms, duration_ms):
     return GenerateTestResults(result_code, result_bundle, statuses,
                                start_ms, duration_ms)
 
   #override
   def TearDown(self):
     pass