Add prefs for collapsed currently open tabs group in new tab page

chrome/common/pref_names.cc

Index: chrome/common/pref_names.cc
diff --git a/chrome/common/pref_names.cc b/chrome/common/pref_names.cc
index 7578e37f1f4b4958bb83aaae11c922d3b4035fce..570f1dd8846a41650bf107671fba4cc0a8813de6 100644
--- a/chrome/common/pref_names.cc
+++ b/chrome/common/pref_names.cc
@@ -1522,6 +1522,9 @@ const char kDisablePluginFinder[] = "plugins.disable_plugin_finder";
 // Customized app page names that appear on the New Tab Page.
 const char kNtpAppPageNames[] = "ntp.app_page_names";
 
+// Keeps track of currently open tabs collapsed state in the Other Devices menu.
+const char kNtpCollapsedCurrentlyOpenTabs[] = "ntp.collapsed_open_tabs";
+
 // Keeps track of which sessions are collapsed in the Other Devices menu.
 const char kNtpCollapsedForeignSessions[] = "ntp.collapsed_foreign_sessions";