Add IPC messages for ARC notification

components/arc/common/arc_instance_messages.h

Index: components/arc/common/arc_instance_messages.h
diff --git a/components/arc/common/arc_instance_messages.h b/components/arc/common/arc_instance_messages.h
index 948704697bc6ef6cbe6347b373e03bfb138742d0..3cb37aae9914a64a2eec43a152258e8418ceb2bb 100644
--- a/components/arc/common/arc_instance_messages.h
+++ b/components/arc/common/arc_instance_messages.h
@@ -10,7 +10,9 @@
 #include "base/file_descriptor_posix.h"
 #include "ipc/ipc_message_macros.h"
 
-#include "components/arc/common/arc_message_types.h"
+// Using relative paths since this file is shared between chromium and android.
+#include "arc_message_types.h"
+#include "arc_notification_types.h"
 
 #define IPC_MESSAGE_START ArcInstanceMsgStart
 
@@ -24,3 +26,13 @@ IPC_MESSAGE_CONTROL3(ArcInstanceMsg_RegisterInputDevice,
                      std::string, /* name */
                      std::string, /* device_type */
                      base::FileDescriptor /* fd */)
+
+// Enum for notification event types.
+IPC_ENUM_TRAITS_MAX_VALUE(arc::ArcNotificationEvent,
+                          arc::ArcNotificationEvent::NOTIFICATION_EVENT_LAST)
+
+// Sends an event from Chrome notification UI to Android.
+// |event| is a type of occured event.
+IPC_MESSAGE_CONTROL2(ArcInstanceMsg_SendNotificationEventToAndroid,
+                     std::string /* key */,
+                     arc::ArcNotificationEvent /* event */);