[Sync] Initial implementation of foreign sessions suggestions provider.

components/ntp_snippets/pref_names.cc

Index: components/ntp_snippets/pref_names.cc
diff --git a/components/ntp_snippets/pref_names.cc b/components/ntp_snippets/pref_names.cc
index 0cf372ece38d3054d8c08294747d21ea9eb7846c..53836bf508f04566684705c88c958222f1482d9b 100644
--- a/components/ntp_snippets/pref_names.cc
+++ b/components/ntp_snippets/pref_names.cc
@@ -29,6 +29,8 @@ const char kDismissedRecentOfflineTabSuggestions[] =
     "ntp_suggestions.offline_pages.recent_tabs.dismissed_ids";
 const char kDismissedDownloadSuggestions[] =
     "ntp_suggestions.offline_pages.downloads.dismissed_ids";
+const char kDismissedForeignSessionsSuggestions[] =
+    "ntp_suggestions.foreign_sessions.dismissed_ids";
 
 const char kBookmarksFirstM54Start[] =
     "ntp_suggestions.bookmarks.first_M54_start";
@@ -47,6 +49,5 @@ const char kUserClassifierLastTimeToShowSuggestions[] =
 const char kUserClassifierLastTimeToUseSuggestions[] =
     "ntp_suggestions.user_classifier.last_time_to_use_suggestions";
 
-
 }  // namespace prefs
 }  // namespace ntp_snippets