Mojo: Cancel WaitingCallbacks when their HandleWrappers are closed.

mojo/mojo_apps.gypi

 # 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.
 
 {
   'targets': [
     {
       # GN version: //mojo/apps/js
       #             //mojo/apps/js/bindings
       #             //mojo/apps/js/bindings/gl
@@ skipping 53 matching lines @@
       'dependencies': [
         '../gin/gin.gyp:gin_test',
         'mojo_base.gyp:mojo_common_lib',
         'mojo_base.gyp:mojo_common_test_support',
         'mojo_base.gyp:mojo_public_test_interfaces',
         'mojo_base.gyp:mojo_run_all_unittests',
         'mojo_apps_js_bindings',
         'mojo_js_lib',
       ],
       'sources': [
+        'apps/js/test/handle_unittest.cc',
         'apps/js/test/js_to_cpp_unittest.cc',
         'apps/js/test/run_apps_js_tests.cc',
       ],
     },
     {
       'target_name': 'mojo_js',
       'type': 'loadable_module',
       'dependencies': [
         'mojo_js_lib',
         '<(mojo_system_for_loadable_module)',
@@ skipping 17 matching lines @@
             'mojo_apps_js_unittests.isolate',
           ],
           'sources': [
             'mojo_apps_js_unittests.isolate',
           ],
         },
       ],
     }],
   ],
 }