Remove GYP for mojo/shell and mojo/services

testing/buildbot/chromium_trybot.json

 {
   "compile_targets": [
     "all"
   ],
   "gtest_tests": [
     "accessibility_unittests",
     "app_list_unittests",
     {
       "test": "ash_unittests",
       "chromium_configs": [
@@ skipping 104 matching lines @@
     "message_center_unittests",
     "mojo_common_unittests",
     "mojo_public_bindings_unittests",
     "mojo_public_environment_unittests",
     "mojo_public_system_unittests",
     "mojo_public_utility_unittests",
     {
       "test": "mojo_application_manager_unittests",
       "platforms": ["linux"]
     },
-    {
-      "test": "mojo_shell_tests",
-      "platforms": ["linux"]
-    },
     "mojo_system_unittests",
     {
       "test": "nacl_loader_unittests",
       "platforms": ["linux"]
     },
     {
       "test": "net_unittests",
       "swarming": {
         "can_use_on_swarming_builders": true
       }
@@ skipping 95 matching lines @@
   "non_filter_tests_builders": [
   ],
 
   "filter_compile_builders": [
     "win_chromium_compile_dbg",
     "win_chromium_rel_swarming",
     "win_chromium_x64_rel_swarming",
     "win8_chromium_rel"
   ]
 }