Updates try bots for aura/ash_unittests

aura_unittests should run on linux and windows (including mac)
ash_unittests should run on chromeos and windows.

BUG=none
TEST=none
R=phajdan.jr@chromium.org

Review URL: https://codereview.chromium.org/282363002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@271430 0039d316-1c4b-4281-b951-d872f2087c98

testing/buildbot/chromium_trybot.json

@@ -57,6 +57,18 @@
     "test": "app_shell_browsertests",
     "chromium_configs": ["chromium_chromeos", "chromium_chromeos_clang"]
   },
+  {
+    "test": "ash_unittests",
+    "chromium_configs": ["chromium_chromeos"]
+  },
+  {
+    "test": "ash_unittests",
+    "platforms": ["win"]
+  },
+  {
+    "test": "aura_unittests",
+    "platforms": ["linux", "win"]
+  },
   {
     "test": "mojo_view_manager_unittests",
     "platforms": ["linux"]