Revert 156678 - Native messaging now uses the MessageService back-end.

chrome/common/extensions/extension_messages.h

Index: chrome/common/extensions/extension_messages.h
diff --git a/chrome/common/extensions/extension_messages.h b/chrome/common/extensions/extension_messages.h
index 9bed1766054c9ac8550c55c10207a991be3569ff..6be2364ea2c17292a204eda057d326df1eb58a12 100644
--- a/chrome/common/extensions/extension_messages.h
+++ b/chrome/common/extensions/extension_messages.h
@@ -451,14 +451,6 @@ IPC_SYNC_MESSAGE_CONTROL4_1(ExtensionHostMsg_OpenChannelToExtension,
                             std::string /* channel_name */,
                             int /* port_id */)
 
-IPC_SYNC_MESSAGE_CONTROL5_1(ExtensionHostMsg_OpenChannelToNativeApp,
-                            int /* routing_id */,
-                            std::string /* source_extension_id */,
-                            std::string /* native_app_name */,
-                            std::string /* channel_name */,
-                            std::string /* connection_message */,
-                            int /* port_id */)
-
 // Get a port handle to the given tab.  The handle can be used for sending
 // messages to the extension.
 IPC_SYNC_MESSAGE_CONTROL4_1(ExtensionHostMsg_OpenChannelToTab,