[Sync] Add version info to about:sync

chrome/browser/sync/sync_ui_util.h

Index: chrome/browser/sync/sync_ui_util.h
diff --git a/chrome/browser/sync/sync_ui_util.h b/chrome/browser/sync/sync_ui_util.h
index 2ded4eba00f322238b4960a76ee570891506438b..3498a63731ae54fa2ae37c0a66a0b5332aca55e4 100644
--- a/chrome/browser/sync/sync_ui_util.h
+++ b/chrome/browser/sync/sync_ui_util.h
@@ -83,5 +83,12 @@ void AddIntSyncDetail(base::ListValue* details,
 void AddStringSyncDetails(ListValue* details, const std::string& stat_name,
                           const std::string& stat_value);
 
+// Returns a string describing the chrome version environment. Version format:
+// <Build Info> <OS> <Version number> (<Last change>)<channel or "-devel">
+// If version information is unavailable, returns "invalid."
+// TODO(zea): this approximately matches MakeUserAgentForSyncApi in
+// sync_backend_host.cc. Unify the two if possible.
+std::string GetVersionString();
+
 }  // namespace sync_ui_util
 #endif  // CHROME_BROWSER_SYNC_SYNC_UI_UTIL_H_