gclient: fix recursedeps tuple/list validation for chromeos

Bug: 727685, 570091
Change-Id: I97a99d15930c1662c0ecfacd3755af27b282f686
Reviewed-on: https://chromium-review.googlesource.com/517800
Reviewed-by: Andrii Shyshkalov <tandrii@chromium.org>
Reviewed-by: Paul Hobbs <phobbs@google.com>
Commit-Queue: Paweł Hajdan Jr. <phajdan.jr@chromium.org>
diff --git a/gclient_eval.py b/gclient_eval.py
index a995db9..1652eb7 100644
--- a/gclient_eval.py
+++ b/gclient_eval.py
@@ -71,7 +71,11 @@
 
     # Whitelists deps for which recursion should be enabled.
     schema.Optional('recursedeps'): [
-        schema.Optional(schema.Or(basestring, (basestring, basestring)))
+        schema.Optional(schema.Or(
+            basestring,
+            (basestring, basestring),
+            [basestring, basestring]
+        )),
     ],
 
     # Blacklists directories for checking 'include_rules'.