Introduce ItemPosition class for enhanced bookmarks.

components/components_tests.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.
 
 {
   'variables': {
     # This turns on e.g. the filename-based detection of which
     # platforms to include source files on (e.g. files ending in
     # _mac.h or _mac.cc are only compiled on MacOSX).
     'chromium_code': 1,
@@ skipping 97 matching lines @@
             'domain_reliability/monitor_unittest.cc',
             'domain_reliability/scheduler_unittest.cc',
             'domain_reliability/test_util.cc',
             'domain_reliability/test_util.h',
             'domain_reliability/uploader_unittest.cc',
             'domain_reliability/util_unittest.cc',
             # Note: GN tests converted to here, need to do the rest.
             'enhanced_bookmarks/enhanced_bookmark_utils_unittest.cc',
             'enhanced_bookmarks/image_store_ios_unittest.mm',
             'enhanced_bookmarks/image_store_unittest.cc',
+            'enhanced_bookmarks/item_position_unittest.cc',
             'enhanced_bookmarks/metadata_accessor_unittest.cc',
             'feedback/feedback_common_unittest.cc',
             'feedback/feedback_data_unittest.cc',
             'feedback/feedback_uploader_unittest.cc',
             'gcm_driver/gcm_account_mapper_unittest.cc',
             'gcm_driver/gcm_client_impl_unittest.cc',
             'gcm_driver/gcm_driver_desktop_unittest.cc',
             'gcm_driver/gcm_stats_recorder_impl_unittest.cc',
             'google/core/browser/google_util_unittest.cc',
             'history/core/browser/url_database_unittest.cc',
@@ skipping 795 matching lines @@
               'dependencies': [
                 '../base/allocator/allocator.gyp:allocator',
               ],
             }],
           ],
         },
       ],
     }],
   ],
 }