Made --enable-rich-notifications flag available to message_center.

ui/message_center/message_center_switches.h

Index: ui/message_center/message_center_switches.h
diff --git a/ui/message_center/message_center_switches.h b/ui/message_center/message_center_switches.h
index a3b7a5d319aa316c3f42c9f6c42fb61e36c518e6..590a98f6ace0e6a189dc4665ba719e79079cc959 100644
--- a/ui/message_center/message_center_switches.h
+++ b/ui/message_center/message_center_switches.h
@@ -21,6 +21,17 @@ namespace switches {
 //  - WebNotificationButtonViewBase: merge into WebNotificationButtonView.
 MESSAGE_CENTER_EXPORT extern const char kDisableNewMessageCenterBubble[];
 
+// Enables rich templated notifications and NotificationCenter.
+MESSAGE_CENTER_EXPORT extern const char kEnableRichNotifications[];
+
+// Enables simple notifications with the new templates defined as part of rich
+// notifications. When kEnableRichNotifications is set those templates will be
+// used regardless of whether this flag is set, but this flag allows us to get
+// the new templates even when kEnableRichNotifications is not set. This is
+// useful for now because the kEnableRichNotifications functionality isn't
+// complete. TODO(dharcourt): Remove when kEnableRichNotifications is ready.
+MESSAGE_CENTER_EXPORT extern const char kEnableNewSimpleNotifications[];
+
 }  // namespace switches
 }  // namespace message_center