video_VideoSanity Autotest: pass for mario/zgb instead of TestNAError

Rather than raise TestNAError, return a pass for these boards.  This is to
prevent confusion about bvt results, as TestNAError is counted as a failure.
Counting a known failure as a pass will be an improvement until
crbug.com/220147 is fixed.

BUG=None
TEST=ran it

Change-Id: I71085e64a6be36b09e26d3005e462d2f001fd5b0
Previous-Reviewed-on: https://chromium-review.googlesource.com/243670
(cherry picked from commit 2fd8d72f0fe1c92ba47b0c70e36aac8e17ad38df)
Reviewed-on: https://chromium-review.googlesource.com/244100
Reviewed-by: Katherine Threlkeld <kathrelkeld@chromium.org>
Commit-Queue: Katherine Threlkeld <kathrelkeld@chromium.org>
Tested-by: Katherine Threlkeld <kathrelkeld@chromium.org>
diff --git a/client/site_tests/video_VideoSanity/video_VideoSanity.py b/client/site_tests/video_VideoSanity/video_VideoSanity.py
index f8e4e04..b086d94 100755
--- a/client/site_tests/video_VideoSanity/video_VideoSanity.py
+++ b/client/site_tests/video_VideoSanity/video_VideoSanity.py
@@ -97,11 +97,11 @@
 
 
     def run_once(self):
-        boards = ['x86-mario', 'x86-zgb']
+        boards_to_skip = ['x86-mario', 'x86-zgb']
         # TODO(scottz): Remove this when crbug.com/220147 is fixed.
         dut_board = utils.get_current_board()
-        if dut_board in boards:
-           raise error.TestNAError('This test is not available on %s' %
-                                    dut_board)
+        if dut_board in boards_to_skip:
+            logging.info("Skipping test run on this board.")
+            return
         with chrome.Chrome() as cr:
             self.run_video_sanity_test(cr.browser)