Optimize startup time of notification code by removing unused code.

ui/message_center/notifier_settings.h

Index: ui/message_center/notifier_settings.h
diff --git a/ui/message_center/notifier_settings.h b/ui/message_center/notifier_settings.h
index b162d766e38c766a2f7d982369fb70431053d0f1..5043ff884f746efaa7b25d32382ca593404c3c6c 100644
--- a/ui/message_center/notifier_settings.h
+++ b/ui/message_center/notifier_settings.h
@@ -116,14 +116,9 @@ struct MESSAGE_CENTER_EXPORT Notifier {
 };
 
 struct MESSAGE_CENTER_EXPORT NotifierGroup {
-  NotifierGroup(const gfx::Image& icon,
-                const base::string16& name,
-                const base::string16& login_info);
+  NotifierGroup(const base::string16& name, const base::string16& login_info);
   ~NotifierGroup();
 
-  // Icon of a notifier group.
-  const gfx::Image icon;
-
   // Display name of a notifier group.
   const base::string16 name;