Enable mojo js tests which depend on mojom.js files in gen/.

mojo/mojo.gyp

 # Copyright 2013 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.
 
 {
   'target_defaults': {
     'conditions': [
       ['mojo_shell_debug_url != ""', {
         'defines': [
           'MOJO_SHELL_DEBUG=1',
@@ skipping 528 matching lines @@
         'bindings/js/unicode.h',
         'bindings/js/waiting_callback.cc',
         'bindings/js/waiting_callback.h',
       ],
     },
     {
       'target_name': 'mojo_js_unittests',
       'type': 'executable',
       'dependencies': [
         '../gin/gin.gyp:gin_test',
+        'mojo_common_test_support',
         'mojo_js_bindings_lib',
         'mojo_run_all_unittests',
         'mojo_public_test_interfaces',
       ],
       'sources': [
         'bindings/js/run_js_tests.cc',
       ],
     },
     {
       'target_name': 'mojo_message_generator',
@@ skipping 165 matching lines @@
             'mojo_js_unittests.isolate',
           ],
           'sources': [
             'mojo_js_unittests.isolate',
           ],
         },
       ],
     }],
   ],
 }