Introduce the plumbing necessary to report Unrecoverable error from model safe workers.

chrome/chrome.gyp

 # Copyright (c) 2011 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': {
     'chromium_code': 1,
 
     'variables': {
       'version_py_path': 'tools/build/version.py',
       'version_path': 'VERSION',
@@ skipping 652 matching lines @@
         'browser/sync/sessions/ordered_commit_set.cc',
         'browser/sync/sessions/ordered_commit_set.h',
         'browser/sync/sessions/session_state.cc',
         'browser/sync/sessions/session_state.h',
         'browser/sync/sessions/status_controller.cc',
         'browser/sync/sessions/status_controller.h',
         'browser/sync/sessions/sync_session.cc',
         'browser/sync/sessions/sync_session.h',
         'browser/sync/sessions/sync_session_context.cc',
         'browser/sync/sessions/sync_session_context.h',
+        'browser/sync/sessions/unrecoverable_error_info.h',
+        'browser/sync/sessions/unrecoverable_error_info.cc',
         'browser/sync/sync_js_controller.cc',
         'browser/sync/sync_js_controller.h',
         'browser/sync/syncable/blob.h',
         'browser/sync/syncable/dir_open_result.h',
         'browser/sync/syncable/directory_backing_store.cc',
         'browser/sync/syncable/directory_backing_store.h',
         'browser/sync/syncable/directory_change_delegate.h',
         'browser/sync/syncable/directory_event.h',
         'browser/sync/syncable/directory_manager.cc',
         'browser/sync/syncable/directory_manager.h',
@@ skipping 1040 matching lines @@
                 'destination': '<(PRODUCT_DIR)/default_apps',
                 'files': ['<@(default_apps_list)']
               },
             ],
           }],
         ],
       }],  # targets
     }],  # OS != "mac"
   ],  # 'conditions'
 }