mojo: Now that mandoline/ is deleted, also remove mojo:clipboard.

mojo/tools/data/apptests

 # This file contains a list of Mojo gtest unit tests.
 #
 # This must be valid Python. It may use the |config| global that will be a
 # mopy.config.Config object, and must set a |tests| global that will contain the
 # list of tests to run.
 #
 # The entries in |tests| are dictionaries of the following form:
 #   {
 #     # Required URL for apptest.
 #     'test': 'mojo:test_app_url',
@@ skipping 13 matching lines @@
 mus_apptests = { 'test': 'mojo:mus_apptests' }
 # osmesa is not used on android, so no flags are needed for
 # mus_apptests.
 if config.target_os != config.OS_ANDROID:
   mus_apptests['args'] = [ '--use-x11-test-config',
                            '--override-use-gl-with-osmesa-for-tests' ]
 
 # WARNING: If you add a test make sure the gn target mojo_apptests depends upon
 # it.
 tests = [
-  {
-    'test': 'mojo:clipboard_apptests',
-    'type': 'gtest_isolated',
-  },
     # TODO(rockot): Flaky. Failing with "Unrecognized --gtest_list_tests output"
     # http://crbug.com/569367.
 #  {
 #    'test': 'mojo:network_service_apptests',
 #    'type': 'gtest_isolated',
 #  },
   {
     'test': 'mojo:resource_provider_apptests',
     'type': 'gtest_isolated',
   },
@@ skipping 39 matching lines @@
     },
     # TODO(sky): enable when works (http://crbug.com/577274 and likely
     # http://crbug.com/569367).
 #    {
 #      'test': 'mojo:views_apptests',
 #      'type': 'gtest_isolated',
 #      'args': ['--use-x11-test-config',
 #               '--override-use-gl-with-osmesa-for-tests', '--enable-logging']
 #    },
   ]