Convert Mojo tests to use swarming.

BUILD.gn

Index: BUILD.gn
diff --git a/BUILD.gn b/BUILD.gn
index 103cf9ab6ce594eb4f87aa4ab0c45f05b4003f6e..1cad2baa0886339eb88db97debd69c97a031cc39 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -638,17 +638,34 @@ group("mojo_apptests") {
   testonly = true
 
   deps = []
+  data_deps = []
+  data = []
 
   if (is_win || is_linux) {
-    deps += [
-      "//components/resource_provider:resource_provider_unittests",
-      "//mash:mash_unittests",
-      "//media/mojo/services:tests",
-      "//ui/views/mus:tests",
+    deps += [ "//services/shell/standalone" ]
+    data_deps = [
+      "//media/mojo/services:media_apptests",
+    ]
+    if (is_linux) {
+      data_deps += [ "//tools/xdisplaycheck" ]
+    }
+    data += [
+      "//mojo/tools/apptest_runner.py",
+      "//mojo/tools/data/apptests",
+      "//mojo/tools/mopy/",
+      "//testing/xvfb.py",
+      "//tools/swarming_client/utils/subprocess42.py",
     ]
   }
 }
 
+group("mojo_apptests_run") {
+  testonly = true
+  deps = [
+    ":mojo_apptests",
+  ]
+}
+
 group("gn_only") {
   testonly = true