autotest: Run desktopui_MashLogin on boards with no internal display.

Running ./chrome --mash on boards with no internal display has been
fixed. Remove an early return in desktopui_MashLogin that skipped boards
with no internal display.

BUG=chromium:673561
TEST=Ran desktopui_MashLogin on stumpy.

Change-Id: Ia941a9d943a83c28ed4a8423b738b9fd7783a689
Reviewed-on: https://chromium-review.googlesource.com/475004
Commit-Ready: Kyle Charbonneau <kylechar@chromium.org>
Tested-by: Kyle Charbonneau <kylechar@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
diff --git a/client/site_tests/desktopui_MashLogin/desktopui_MashLogin.py b/client/site_tests/desktopui_MashLogin/desktopui_MashLogin.py
index 4ec4146..df45c93 100644
--- a/client/site_tests/desktopui_MashLogin/desktopui_MashLogin.py
+++ b/client/site_tests/desktopui_MashLogin/desktopui_MashLogin.py
@@ -16,14 +16,6 @@
     def run_once(self):
         """Entry point of this test."""
 
-        # Mash requires a connected display to start chrome. Chromebox and
-        # Chromebit devices in the lab run without a connected display.
-        # Limit this test to devices with a built-in display until we can fix
-        # mash. http://crbug.com/673561
-        if utils.get_board_type() not in ['CHROMEBOOK', 'CHROMEBASE']:
-            logging.warning('chrome --mash requires a display, skipping test.')
-            return
-
         # The test is sometimes flaky on these boards. Mash doesn't target
         # hardware this old, so skip the test. http://crbug.com/679213
         boards_to_skip = ['x86-mario', 'x86-alex', 'x86-alex_he', 'x86-zgb',