[Sync] Creating sync_sessions component, moving revisit logic.

components/sync_driver/BUILD.gn

 # 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.
 
 import("//build/config/features.gni")
 
 source_set("sync_driver") {
   sources = [
     "about_sync_util.cc",
     "about_sync_util.h",
@@ skipping 65 matching lines @@
     "open_tabs_ui_delegate.h",
     "pref_names.cc",
     "pref_names.h",
     "profile_sync_auth_provider.cc",
     "profile_sync_auth_provider.h",
     "profile_sync_components_factory.h",
     "protocol_event_observer.cc",
     "protocol_event_observer.h",
     "proxy_data_type_controller.cc",
     "proxy_data_type_controller.h",
-    "revisit/current_tab_matcher.cc",
-    "revisit/current_tab_matcher.h",
-    "revisit/offset_tab_matcher.cc",
-    "revisit/offset_tab_matcher.h",
-    "revisit/page_equality.h",
-    "revisit/page_visit_observer.h",
-    "revisit/sessions_page_revisit_observer.cc",
-    "revisit/sessions_page_revisit_observer.h",
     "sessions/synced_window_delegates_getter.cc",
     "sessions/synced_window_delegates_getter.h",
     "shared_change_processor.cc",
     "shared_change_processor.h",
     "shared_change_processor_ref.cc",
     "shared_change_processor_ref.h",
     "signin_manager_wrapper.cc",
     "signin_manager_wrapper.h",
     "sync_api_component_factory.h",
     "sync_client.cc",
@@ skipping 103 matching lines @@
     "about_sync_util_unittest.cc",
     "backup_rollback_controller_unittest.cc",
     "data_type_manager_impl_unittest.cc",
     "device_info_data_type_controller_unittest.cc",
     "device_info_sync_service_unittest.cc",
     "favicon_cache_unittest.cc",
     "generic_change_processor_unittest.cc",
     "model_association_manager_unittest.cc",
     "non_blocking_data_type_controller_unittest.cc",
     "non_ui_data_type_controller_unittest.cc",
-    "revisit/current_tab_matcher_unittest.cc",
-    "revisit/offset_tab_matcher_unittest.cc",
-    "revisit/sessions_page_revisit_observer_unittest.cc",
     "shared_change_processor_unittest.cc",
     "sync_prefs_unittest.cc",
     "sync_stopped_reporter_unittest.cc",
     "sync_util_unittest.cc",
     "system_encryptor_unittest.cc",
     "tab_node_pool_unittest.cc",
     "ui_data_type_controller_unittest.cc",
   ]
   deps = [
     ":test_support",
     "//testing/gmock",
     "//testing/gtest",
   ]
 
   if (enable_configuration_policy) {
     sources += [ "sync_policy_handler_unittest.cc" ]
   }
 }