cros: Clean up screenlockPrivate plumbing.

chrome/browser/signin/screenlock_bridge.h

Index: chrome/browser/signin/screenlock_bridge.h
diff --git a/chrome/browser/signin/screenlock_bridge.h b/chrome/browser/signin/screenlock_bridge.h
index cce1b7c2958e53ef2c6102439489da1e0c655b06..3859e3d56eccf8b39668762251cefcc1c3196878 100644
--- a/chrome/browser/signin/screenlock_bridge.h
+++ b/chrome/browser/signin/screenlock_bridge.h
@@ -5,7 +5,8 @@
 #ifndef CHROME_BROWSER_SIGNIN_SCREENLOCK_BRIDGE_H_
 #define CHROME_BROWSER_SIGNIN_SCREENLOCK_BRIDGE_H_
 
-#include "base/callback_forward.h"
+#include <string>
+
 #include "base/lazy_instance.h"
 #include "base/macros.h"
 #include "base/observer_list.h"
@@ -46,10 +47,8 @@ class ScreenlockBridge {
     virtual void ShowBannerMessage(const std::string& message) = 0;
 
     // Shows a button inside the user pod on the lock screen with an icon.
-    // |callback| is invoked when the icon is clicked. This is deprecated now.
     virtual void ShowUserPodButton(const std::string& user_email,
-                                   const gfx::Image& icon,
-                                   const base::Closure& callback) = 0;
+                                   const gfx::Image& icon) = 0;
 
     // Hides the user pod button for a user.
     virtual void HideUserPodButton(const std::string& user_email) = 0;