Mojo C++ bindings: remove the utility/ folder.

mojo/mojo_public_utility_unittests.isolate

-# Copyright 2015 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': [
-    '../base/base.isolate',
-  ],
-  'conditions': [
-    ['OS=="win" or OS=="mac" or OS=="linux"', {
-      'variables': {
-        'command': [
-          '../testing/test_env.py',
-          '<(PRODUCT_DIR)/mojo_public_utility_unittests<(EXECUTABLE_SUFFIX)',
-          '--brave-new-test-launcher',
-          '--test-launcher-bot-mode',
-        ],
-        'files': [
-          '../testing/test_env.py',
-        ],
-      },
-    }],
-    ['OS=="win"', {
-      'variables': {
-        'files': [
-          '<(PRODUCT_DIR)/mojo_public_test_support.dll',
-        ],
-      },
-    }],
-    ['OS=="linux"', {
-      'variables': {
-        'files': [
-          '<(PRODUCT_DIR)/lib/libmojo_public_test_support.so',
-        ],
-      },
-    }],
-    ['OS=="mac"', {
-      'variables': {
-        'files': [
-          '<(PRODUCT_DIR)/libmojo_public_test_support.dylib',
-        ],
-      },
-    }],
-  ],
-}