Add Android device type for NVIDIA Shield

tools/buildbot_spec.py

 #
 # Copyright 2015 Google Inc.
 #
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 #
 
 #!/usr/bin/env python
 
 usage = '''
@@ skipping 245 matching lines @@
   return None
 
 
 cov_skip.extend([lineno(), lineno() + 1])
 def product_board(builder_dict):
   if 'Android' in builder_dict.get('os', ''):
     return {
       'AndroidOne':    None,  # TODO(borenet,kjlubick)
       'GalaxyS3':      'm0',  #'smdk4x12', Detected incorrectly by swarming?
       'GalaxyS4':      None,  # TODO(borenet,kjlubick)
-      'NVIDIA_Shield': None,  # TODO(borenet,kjlubick)
+      'NVIDIA_Shield': 'foster',
       'Nexus10':       'manta',
       'Nexus5':        'hammerhead',
       'Nexus6':        'shamu',
       'Nexus7':        'grouper',
       'Nexus7v2':      'flo',
       'Nexus9':        'flounder',
       'NexusPlayer':   'fugu',
     }[builder_dict['model']]
   return None
 
@@ skipping 129 matching lines @@
   if len(sys.argv) == 2 and sys.argv[1] == 'test':
     self_test()
     sys.exit(0)
 
   if len(sys.argv) != 3:
     print usage
     sys.exit(1)
 
   with open(sys.argv[1], 'w') as out:
     json.dump(get_builder_spec(sys.argv[2]), out)