Add IPC messages for ARC notification

components/arc/common/arc_host_messages.h

Index: components/arc/common/arc_host_messages.h
diff --git a/components/arc/common/arc_host_messages.h b/components/arc/common/arc_host_messages.h
index d4d72fe27c79c536259e795db5f6a4b69ae061cf..15eef98ce16944008511af66be8f6eeb6858d886 100644
--- a/components/arc/common/arc_host_messages.h
+++ b/components/arc/common/arc_host_messages.h
@@ -7,6 +7,16 @@
 
 #include "ipc/ipc_message_macros.h"
 
+// Using relative paths since this file is shared between chromium and android.
+#include "arc_message_param_traits.h"
+#include "arc_notification_types.h"
+
 #define IPC_MESSAGE_START ArcInstanceHostMsgStart
 
 IPC_MESSAGE_CONTROL0(ArcInstanceHostMsg_InstanceReady)
+
+IPC_MESSAGE_CONTROL1(ArcInstanceHostMsg_NotificationPosted,

[khmel1, 2015/11/25 00:30:10]

Comments are expected here, please take a look at
ArcInstanceMsg_RegisterInputDevice for example

[yoshiki, 2015/11/25 09:40:35]

Done.

+                     arc::ArcNotificationData);
+
+IPC_MESSAGE_CONTROL1(ArcInstanceHostMsg_NotificationRemoved,
+                     std::string /* key */);