Add a sign-in promo message to the Other Devices menu.

chrome/browser/ui/webui/ntp/foreign_session_handler.h

Index: chrome/browser/ui/webui/ntp/foreign_session_handler.h
diff --git a/chrome/browser/ui/webui/ntp/foreign_session_handler.h b/chrome/browser/ui/webui/ntp/foreign_session_handler.h
index 4f823166882c5b656fd8b5454e1e12eaae4b1633..0d8c1a33d14c677e928610d7a10db63afa849f1a 100644
--- a/chrome/browser/ui/webui/ntp/foreign_session_handler.h
+++ b/chrome/browser/ui/webui/ntp/foreign_session_handler.h
@@ -37,6 +37,9 @@ class ForeignSessionHandler : public content::WebUIMessageHandler,
   // Returns a pointer to the current session model associator or NULL.
   SessionModelAssociator* GetModelAssociator();
 
+  // Returns true if tab sync is enabled for this profile, otherwise false.
+  bool IsTabSyncEnabled();
+
   // Determines which session is to be opened, and then calls
   // OpenForeignSession, to begin the process of opening a new browser window.
   // This is a javascript callback handler.