Update Mac notification tray behavior.

ui/message_center/notification_list.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/message_center/notification_list.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/stl_util.h"
 #include "base/time/time.h"
@@ skipping 298 matching lines @@
 
 size_t NotificationList::NotificationCount() const {
   return notifications_.size();
 }
 
 void NotificationList::SetQuietModeInternal(bool quiet_mode) {
   quiet_mode_ = 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;
   }
 }
 
 NotificationList::Notifications::iterator
     NotificationList::GetNotification(const std::string& id) {
   for (Notifications::iterator iter = notifications_.begin();
        iter != notifications_.end(); ++iter) {
     if ((*iter)->id() == id)
       return iter;
   }
@@ skipping 14 matching lines @@
   bool state_inherited = false;
   if (iter != notifications_.end()) {
     notification->CopyState(*iter);
     state_inherited = true;
     EraseNotification(iter);
   }
   // Add the notification to the the list and mark it unread and unshown.
   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
   // in EraseNotification(), which will delete it.
   notifications_.insert(notification.release());
 }
 
 }  // namespace message_center