Update Mac notification tray behavior.

ui/message_center/notification_list.cc

Index: ui/message_center/notification_list.cc
diff --git a/ui/message_center/notification_list.cc b/ui/message_center/notification_list.cc
index 8f1bc9f67e6d3b9c0d3a83754465529695110f7b..501212ef7e149ef11ecb4c6c7e749e599195806b 100644
--- a/ui/message_center/notification_list.cc
+++ b/ui/message_center/notification_list.cc
@@ -316,10 +316,8 @@ void NotificationList::SetQuietModeInternal(bool quiet_mode) {
   if (quiet_mode_) {
     for (Notifications::iterator iter = notifications_.begin();
          iter != notifications_.end(); ++iter) {
-      (*iter)->set_is_read(true);
       (*iter)->set_shown_as_popup(true);
     }
-    unread_count_ = 0;
   }
 }
 
@@ -354,9 +352,9 @@ void NotificationList::PushNotification(scoped_ptr<Notification> notification) {
   if (!state_inherited) {
     // TODO(mukai): needs to distinguish if a notification is dismissed by
     // the quiet mode or user operation.
-    notification->set_is_read(quiet_mode_);
+    notification->set_is_read(false);
     notification->set_shown_as_popup(message_center_visible_ || quiet_mode_);
-    if (!quiet_mode_ && notification->priority() > MIN_PRIORITY)
+    if (notification->priority() > MIN_PRIORITY)
         ++unread_count_;
   }
   // Take ownership. The notification can only be removed from the list