Add full reboot option

The current reboot test uses 'reboot' command. However, this doesn't
necessarily exercise the full power sequence. This change provides a new
reboot option 'full_reboot' which performs the following:
  - AP shutdown
  - EC reboot
  - AP power-up
The new full reboot option should provide us a slightly different test
coverage.

BUG=chrome-os-partner:16645
TEST=Run full reboot step

Change-Id: I14ab15c4100ecf269478a7faa99a089f13ed6a45
Signed-off-by: Vic (Chun-Ju) Yang <victoryang@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/197241
diff --git a/py/goofy/goofy.py b/py/goofy/goofy.py
index 046d3e9..d095c1e 100755
--- a/py/goofy/goofy.py
+++ b/py/goofy/goofy.py
@@ -416,7 +416,7 @@
     """Starts shutdown procedure.
 
     Args:
-      operation: The shutdown operation (reboot or halt).
+      operation: The shutdown operation (reboot, full_reboot, or halt).
     """
     active_tests = []
     for test in self.test_list.walk():