Remove ash_unittests/mash_unittests from Windows build targets

mash/example/BUILD.gn

Index: mash/example/BUILD.gn
diff --git a/mash/example/BUILD.gn b/mash/example/BUILD.gn
index e46baab38ddab1daf5bc8d47fd0f4e99b3ba432a..87d532a21f8c8488f3b3390055f6ba9e6b6bb24d 100644
--- a/mash/example/BUILD.gn
+++ b/mash/example/BUILD.gn
@@ -8,7 +8,6 @@ group("example") {
   testonly = true
 
   deps = [
-    "//ash/mus",

[sky, 2016/12/02 17:04:26]

The idea with this dep is if you build mash/example you would have everything
needed to run mash. So, should this dep be conditional based on chromeos?

[James Cook, 2016/12/02 18:38:55]

Done. Should I also add a dep on simple_wm for Windows?

[sky, 2016/12/02 18:57:06]

How about always adding the dep on simple_wm. That way if people want to switch
(there is a command line to change the wm) they won't need to remember to build
simple_wm too.

[James Cook, 2016/12/02 19:12:21]

Done.

     "//mash/example/views_examples",
     "//mash/example/window_type_launcher",
     "//services/service_manager/standalone",