diff --git a/chrome/browser/ui/singleton_tabs.h b/chrome/browser/ui/singleton_tabs.h
index 0f579aa..71397c3 100644
--- a/chrome/browser/ui/singleton_tabs.h
+++ b/chrome/browser/ui/singleton_tabs.h
@@ -31,8 +31,8 @@
 // Creates a NavigateParams struct for a singleton tab navigation.
 NavigateParams GetSingletonTabNavigateParams(Browser* browser, const GURL& url);
 
-// If the given navigational URL is a Singleton, return the tab index for it.
-// Otherwise, returns -1.
-int GetIndexOfSingletonTab(NavigateParams* params);
+// If the given navigational URL is already open in |params->browser|, return
+// the tab index for it. Otherwise, returns -1.
+int GetIndexOfExistingTab(NavigateParams* params);
 
 #endif  // CHROME_BROWSER_UI_SINGLETON_TABS_H_