[Android] Implement gtest and local in platform mode.

build/android/pylib/base/environment_factory.py

Index: build/android/pylib/base/environment_factory.py
diff --git a/build/android/pylib/base/environment_factory.py b/build/android/pylib/base/environment_factory.py
index 3ad39fc6f1bed1ba981b68b14081965daa55c896..31b4952ac16480b4885f65ec11736ffcf1acf352 100644
--- a/build/android/pylib/base/environment_factory.py
+++ b/build/android/pylib/base/environment_factory.py
@@ -2,13 +2,16 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+from pylib import constants
+from pylib.local.device import local_device_environment
 from pylib.remote.device import remote_device_environment
 
 def CreateEnvironment(args, error_func):
 
-  # TODO(jbudorick) Add local device environment.
-  # TODO(jbudorick) Add local machine environment.
-
+  if args.environment == 'local':
+    if args.command not in constants.LOCAL_MACHINE_TESTS:
+      return local_device_environment.LocalDeviceEnvironment(args, error_func)
+    # TODO(jbudorick) Add local machine environment.
   if args.environment == 'remote_device':
     return remote_device_environment.RemoteDeviceEnvironment(args,
                                                              error_func)