sync: make scheduling logic and job ownership more obvious.

sync/sync.gyp

 # Copyright (c) 2012 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,
   },
   'targets': [
     # The core sync library.
@@ skipping 102 matching lines @@
         'engine/resolve_conflicts_command.cc',
         'engine/resolve_conflicts_command.h',
         'engine/store_timestamps_command.cc',
         'engine/store_timestamps_command.h',
         'engine/sync_engine_event.cc',
         'engine/sync_engine_event.h',
         'engine/sync_scheduler.cc',
         'engine/sync_scheduler.h',
         'engine/sync_scheduler_impl.cc',
         'engine/sync_scheduler_impl.h',
+        'engine/sync_session_job.cc',
+        'engine/sync_session_job.h',
         'engine/syncer.cc',
         'engine/syncer.h',
         'engine/syncer_command.cc',
         'engine/syncer_command.h',
         'engine/syncer_proto_util.cc',
         'engine/syncer_proto_util.h',
         'engine/syncer_types.h',
         'engine/syncer_util.cc',
         'engine/syncer_util.h',
         'engine/throttled_data_type_tracker.cc',
@@ skipping 468 matching lines @@
           'internal_api/public/engine/model_safe_worker_unittest.cc',
           'internal_api/public/util/immutable_unittest.cc',
           'engine/apply_control_data_updates_unittest.cc',
           'engine/apply_updates_command_unittest.cc',
           'engine/backoff_delay_provider_unittest.cc',
           'engine/build_commit_command_unittest.cc',
           'engine/download_updates_command_unittest.cc',
           'engine/model_changing_syncer_command_unittest.cc',
           'engine/process_commit_response_command_unittest.cc',
           'engine/process_updates_command_unittest.cc',
+          'engine/sync_session_job_unittest.cc',
           'engine/sync_scheduler_unittest.cc',
           'engine/sync_scheduler_whitebox_unittest.cc',
           'engine/syncer_proto_util_unittest.cc',
           'engine/syncer_unittest.cc',
           'engine/throttled_data_type_tracker_unittest.cc',
           'engine/traffic_recorder_unittest.cc',
           'js/js_arg_list_unittest.cc',
           'js/js_event_details_unittest.cc',
           'js/sync_js_controller_unittest.cc',
           'protocol/proto_enum_conversions_unittest.cc',
@@ skipping 279 matching lines @@
           'variables': {
             'test_suite_name': 'sync_unit_tests',
             'input_shlib_path': '<(SHARED_LIB_DIR)/<(SHARED_LIB_PREFIX)sync_unit_tests<(SHARED_LIB_SUFFIX)',
           },
           'includes': [ '../build/apk_test.gypi' ],
         },
       ],
     }],
   ],
 }