Convert mojo_common_unittests to run exclusively on Swarming

mojo/mojo_base.gyp

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # Essential components (and their tests) that are needed to build
 # Chrome should be here.  Other components that are useful only in
 # Mojo land like mojo_shell should be in mojo.gyp.
 {
   'includes': [
     '../third_party/mojo/mojo_variables.gypi',
@@ skipping 325 matching lines @@
           'dependencies': [
             '../base/base.gyp:base_java',
             'libmojo_system_java',
             '../third_party/mojo/mojo_public.gyp:mojo_public_java',
           ],
           'variables': {
             'java_in_dir': '<(DEPTH)/mojo/android/system',
           },
           'includes': [ '../build/java.gypi' ],
         },
-      ]
-    }]
+      ],
+    }],
+    ['test_isolation_mode != "noop"', {
+      'targets': [
+        {
+          'target_name': 'mojo_common_unittests_run',
+          'type': 'none',
+          'dependencies': [
+            'mojo_common_unittests',
+          ],
+          'includes': [
+            '../build/isolate.gypi',
+          ],
+          'sources': [
+            'mojo_common_unittests.isolate',
+          ],
+        },
+      ],
+    }],
   ]
 }