Remove mojo/apps/js, it is unused

mojo/mojo_apps_js_unittests.isolate

-# 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.
-{
-  'includes': [
-    '../third_party/icu/icu.isolate',
-  ],
-  'conditions': [
-    ['OS=="win" or OS=="mac" or OS=="linux"', {
-      'variables': {
-        'command': [
-          '../testing/test_env.py',
-          '<(PRODUCT_DIR)/mojo_apps_js_unittests<(EXECUTABLE_SUFFIX)',
-          '--brave-new-test-launcher',
-          '--test-launcher-bot-mode',
-        ],
-        'files': [
-          '../gin/test/expect.js',
-          '../testing/test_env.py',
-          '<(PRODUCT_DIR)/gen/mojo/public/interfaces/bindings/tests/',
-          '<(PRODUCT_DIR)/mojo_apps_js_unittests<(EXECUTABLE_SUFFIX)',
-          'apps/js/',
-          'bindings/js/',
-          'public/js/bindings/',
-        ],
-      },
-    }],
-    ['OS=="win"', {
-      'variables': {
-        'files': [
-          '<(PRODUCT_DIR)/mojo_test_support.dll',
-        ],
-      },
-    }],
-    ['OS=="linux"', {
-      'variables': {
-        'files': [
-          '<(PRODUCT_DIR)/lib/libmojo_test_support.so',
-        ],
-      },
-    }],
-    ['OS=="mac"', {
-      'variables': {
-        'files': [
-          '<(PRODUCT_DIR)/libmojo_test_support.dylib',
-        ],
-      },
-    }],
-  ],
-}