[Sync] Move sessions files from sync_driver to sync_sessions.

components/sync_sessions.gypi

Index: components/sync_sessions.gypi
diff --git a/components/sync_sessions.gypi b/components/sync_sessions.gypi
index 1e6901830d9425328d2f7bf4b8350f5181b4ed74..5b0e1a744c65801b9aa355b9f9cce3e03e3905f7 100644
--- a/components/sync_sessions.gypi
+++ b/components/sync_sessions.gypi
@@ -25,6 +25,8 @@
         'sync_sessions/favicon_cache.cc',
         'sync_sessions/favicon_cache.h',
         'sync_sessions/local_session_event_router.h',
+        'sync_sessions/open_tabs_ui_delegate.cc',
+        'sync_sessions/open_tabs_ui_delegate.h',
         'sync_sessions/revisit/bookmarks_by_url_provider_impl.cc',
         'sync_sessions/revisit/bookmarks_by_url_provider_impl.h',
         'sync_sessions/revisit/bookmarks_page_revisit_observer.cc',
@@ -49,10 +51,17 @@
         'sync_sessions/sessions_sync_manager.h',
         'sync_sessions/synced_tab_delegate.cc',
         'sync_sessions/synced_tab_delegate.h',
+        'sync_sessions/synced_session.cc',
+        'sync_sessions/synced_session.h',
         'sync_sessions/synced_session_tracker.cc',
         'sync_sessions/synced_session_tracker.h',
+        'sync_sessions/synced_window_delegate.h',
+        'sync_sessions/synced_window_delegates_getter.cc',
+        'sync_sessions/synced_window_delegates_getter.h',
         'sync_sessions/sync_sessions_client.cc',
         'sync_sessions/sync_sessions_client.h',
+        'sync_sessions/tab_node_pool.cc',
+        'sync_sessions/tab_node_pool.h',
       ],
       'conditions': [
         ['OS!="ios"', {