Add option to android test_runner to specify what devices to run on.

BUG=612360

Review-Url: https://codereview.chromium.org/2045583004
Cr-Original-Commit-Position: refs/heads/master@{#398609}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 8a61f0862d71b51516175fc5903082ca1c495f55

android/pylib/local/device/local_device_environment.py

@@ -11,6 +11,7 @@ import threading
 
 from devil.android import device_blacklist
 from devil.android import device_errors
+from devil.android import device_list
 from devil.android import device_utils
 from devil.android import logcat_monitor
 from devil.utils import file_utils
@@ -41,23 +42,27 @@ class LocalDeviceEnvironment(environment.Environment):
     self._logcat_output_file = args.logcat_output_file
     self._max_tries = 1 + args.num_retries
     self._skip_clear_data = args.skip_clear_data
+    self._target_devices_file = args.target_devices_file
     self._tool_name = args.tool
 
   #override
   def SetUp(self):
-    available_devices = device_utils.DeviceUtils.HealthyDevices(
+    device_arg = 'default'
+    if self._target_devices_file:
+      device_arg = device_list.GetPersistentDeviceList(
+          self._target_devices_file)
+      if not device_arg:
+        logging.warning('No target devices specified. Falling back to '
+                        'running on all available devices.')
+        device_arg = 'default'
+    elif self._device_serial:
+      device_arg = self._device_serial
+
+    self._devices = device_utils.DeviceUtils.HealthyDevices(
         self._blacklist, enable_device_files_cache=self._enable_device_cache,
-        default_retries=self._max_tries - 1)
-    if not available_devices:
-      raise device_errors.NoDevicesError
-    if self._device_serial:
-      self._devices = [d for d in available_devices
-                       if d.adb.GetDeviceSerial() == self._device_serial]
+        default_retries=self._max_tries - 1, device_arg=device_arg)
     if not self._devices:
-        raise device_errors.DeviceUnreachableError(
-            'Could not find device %r' % self._device_serial)
-    else:
-      self._devices = available_devices
+      raise device_errors.NoDevicesError
 
     if self._enable_device_cache:
       for d in self._devices:

android/test_runner.py

@@ -227,6 +227,10 @@ def AddDeviceOptions(parser):
                      help='Do not wipe app data between tests. Use this to '
                      'speed up local development and never on bots '
                      '(increases flakiness)')
+  group.add_argument('--target-devices-file',
+                     help='Path to file with json list of device serials to '
+                          'run tests on. When not specified, all available '
+                          'devices are used.')
 
 
 def AddGTestOptions(parser):