Add a new method to the ProfileInfoCacheObserver for signin status changes.

chrome/browser/ui/webui/signin/user_manager_screen_handler.cc

Index: chrome/browser/ui/webui/signin/user_manager_screen_handler.cc
diff --git a/chrome/browser/ui/webui/signin/user_manager_screen_handler.cc b/chrome/browser/ui/webui/signin/user_manager_screen_handler.cc
index 37c3e9fcb0a7f52ef26acf11460c46e12ab424c9..b88944046fd3ae79f4a5832ccc446d4f2498549e 100644
--- a/chrome/browser/ui/webui/signin/user_manager_screen_handler.cc
+++ b/chrome/browser/ui/webui/signin/user_manager_screen_handler.cc
@@ -140,12 +140,6 @@ class UserManagerScreenHandler::ProfileUpdateObserver
     user_manager_handler_->SendUserList();
   }
 
-  virtual void OnProfileWillBeRemoved(
-      const base::FilePath& profile_path) OVERRIDE {
-    // No-op. When the profile is actually removed, OnProfileWasRemoved
-    // will be called.
-  }
-
   virtual void OnProfileNameChanged(
       const base::FilePath& profile_path,
       const base::string16& old_profile_name) OVERRIDE {
@@ -157,6 +151,11 @@ class UserManagerScreenHandler::ProfileUpdateObserver
     user_manager_handler_->SendUserList();
   }
 
+  virtual void OnProfileSigninRequiredChanged(
+      const base::FilePath& profile_path) OVERRIDE {
+    user_manager_handler_->SendUserList();
+  }
+
   ProfileManager* profile_manager_;
 
   UserManagerScreenHandler* user_manager_handler_;  // Weak; owns us.