Notifications: Add cross-platform UMA: ShowMessageCenter, ShowSettings.

ui/message_center/message_center_types.h

Index: ui/message_center/message_center_types.h
diff --git a/ui/message_center/message_center_types.h b/ui/message_center/message_center_types.h
new file mode 100644
index 0000000000000000000000000000000000000000..280926f96d8ea975b9653f6a2d8a5f040cb36c56
--- /dev/null
+++ b/ui/message_center/message_center_types.h
@@ -0,0 +1,21 @@
+// 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.
+
+#ifndef UI_MESSAGE_CENTER_MESSAGE_CENTER_TYPES_H_
+#define UI_MESSAGE_CENTER_MESSAGE_CENTER_TYPES_H_
+
+namespace message_center {
+
+enum Visibility {
+  // When nothing or just toast popups are being displayed.
+  VISIBILITY_TRANSIENT = 0,
+  // When the message center view is being displayed.
+  VISIBILITY_MESSAGE_CENTER,
+  // When the settings view is being displayed.
+  VISIBILITY_SETTINGS
+};
+
+}  // namespace message_center
+
+#endif  // UI_MESSAGE_CENTER_MESSAGE_CENTER_TYPES_H_