Eliminate Mojo Apptests.

Now we have ShellTests which are canonical gtest unittest executables, we don't need apptests. This change:

- converts media_apptest to a shelltest, media_mojo_unittest
- stops building the media pipeline integration apptest. Currently doesn't compile due to google c++ style guide violations. Was already disabled as an apptest, so even when I patch it to build, it fails.
- deletes native_apptest since it isn't needed anymore given the rest of the shell's test suite.
- eliminates apptest support infrastructure from the shell client lib & scripts.

[email protected],[email protected],[email protected],[email protected]
BUG=

Review-Url: https://codereview.chromium.org/1926973002
Cr-Commit-Position: refs/heads/master@{#390794}
diff --git a/testing/buildbot/gn_isolate_map.pyl b/testing/buildbot/gn_isolate_map.pyl
index c6d0c9e..77ef6f8 100644
--- a/testing/buildbot/gn_isolate_map.pyl
+++ b/testing/buildbot/gn_isolate_map.pyl
@@ -364,6 +364,10 @@
     "label": "//media:media_unittests",
     "type": "windowed_test_launcher",
   },
+  "media_mojo_shell_unittests": {
+    "label": "//media/mojo/services:media_mojo_shell_unittests",
+    "type": "console_test_launcher",
+  },
   "media_blink_unittests": {
     "label": "//media/blink:media_blink_unittests",
     "type": "windowed_test_launcher",
@@ -372,14 +376,6 @@
     "label": "//media/midi:midi_unittests",
     "type": "windowed_test_launcher",
   },
-  "mojo_apptests": {
-    "label": ":mojo_apptests",
-    "type": "script",
-    "script": "//mojo/tools/apptest_runner.py",
-    "args": [
-      '.',
-    ],
-  },
   "mojo_common_unittests": {
     "label": "//mojo/common:mojo_common_unittests",
     "type": "console_test_launcher",