Changes the OnClick behavior in message center.

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/time.h"
 #include "base/values.h"
@@ skipping 243 matching lines @@
   }
 }
 
 void NotificationList::MarkPopupsAsShown(int priority) {
   Notifications::iterator first, last;
   GetPopupIterators(priority, first, last);
   for (Notifications::iterator iter = first; iter != last; ++iter)
     iter->shown_as_popup = true;
 }
 
+void NotificationList::MarkSinglePopupAsShown(const std::string& id) {
+  Notifications::iterator iter;
+  if (!GetNotification(id, &iter))
+    return;
+
+  if (iter->shown_as_popup)
+    return;
+
+  // Moves the item to the beginning of the already-shown items.
+  Notification notification = *iter;
+  notification.shown_as_popup = true;
+  notifications_[notification.priority].erase(iter);
+  for (Notifications::iterator iter2 =
+           notifications_[notification.priority].begin();
+       iter2 != notifications_[notification.priority].end(); iter2++) {
+    if (iter2->shown_as_popup) {
+      notifications_[notification.priority].insert(iter2, notification);
+      return;
+    }
+  }
+
+  // No notifications are already shown as popup, so just re-adding at the end
+  // of the list.
+  notifications_[notification.priority].push_back(notification);
+}
+
 void NotificationList::SetQuietMode(bool quiet_mode) {
   SetQuietModeInternal(quiet_mode);
   quiet_mode_timer_.reset();
 }
 
 void NotificationList::EnterQuietModeWithExpire(
     const base::TimeDelta& expires_in) {
   if (quiet_mode_timer_.get()) {
     // Note that the capital Reset() is the method to restart the timer, not
     // scoped_ptr::reset().
@@ skipping 113 matching lines @@
     popup_count++;
     // No limits for HIGH/MAX priority.
     if (priority == ui::notifications::DEFAULT_PRIORITY &&
         popup_count >= kMaxVisiblePopupNotifications) {
       break;
     }
   }
 }
 
 }  // namespace message_center