Moved some message center constants to message_center_constants.h.

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 087b68d4aae8d42c34cce34a3497386605019d17..64d32c06f0c0f7828d7e8dfae964cd7e0979d282 100644
--- a/ui/message_center/notification_list.cc
+++ b/ui/message_center/notification_list.cc
@@ -9,6 +9,7 @@
 #include "base/stl_util.h"
 #include "base/time.h"
 #include "base/values.h"
+#include "ui/message_center/message_center_constants.h"
 #include "ui/message_center/notification.h"
 #include "ui/message_center/notification_types.h"
 
@@ -35,9 +36,6 @@ bool CompareTimestampSerial::operator()(Notification* n1, Notification* n2) {
   return false;
 }
 
-const size_t NotificationList::kMaxVisibleMessageCenterNotifications = 100;
-const size_t NotificationList::kMaxVisiblePopupNotifications = 3;
-
 NotificationList::NotificationList()
     : message_center_visible_(false),
       unread_count_(0),